Electrical System -- A Case of Bad Nerves

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The electrical system in your car can be likened to the central nervous system in your body. Without it, none of the other organs can function. Generally, electrical system malfunctions are extremely difficult to locate, because there are, quite simply, so many things that can go wrong. The problem could be anything from a blown fuse to a defective starter.

When you turn your key to the “Start” position, a myriad of things happen instantly. Electricity is supplied by the battery, routing it to the electronic engine control computer (if your car is so equipped) which goes to a “start” mode to activate the fuel pump to supply extra fuel for starting. Simultaneously the starter receives its charge and spins the flywheel, which is connected to the crankshaft in your engine between the rear of the engine and the transmission. The crankshaft rotates the pistons which build compression in the cylinders. The coil also receives electricity and sends it to the distributor, which routes it to the spark plugs that ignite the compressed air/fuel mixture in your cylinders, and PRESTO! the car starts and you’re off to the grocery store. In a perfect world, this happens every time you start your car.

Now I could write an entire book on the electrical system of your car, as many people have. There are numerous books and web sites on the subject if you care to know more. But for our purposes, I’ll limit the discussion to batteries, starters and alternators (the starting and charging circuits). These parts can certainly be considered R and R components. They are frequently diagnosed, removed and replaced as a regular staple in auto repair. My purpose is to inform you how these systems interact with each other, how they should be maintained and what you can expect when these parts need to be replaced.


The battery’s main function is to supply initial voltage boost to start the engine. Thereafter, it supplies voltage to sub-systems that require it. It is continually recharged by the alternator, which supplies electricity to the battery when the engine is running. To know why batteries malfunction a little theory on their operation is necessary.


The battery performs the following four basic functions in a vehicle:

1. It supplies a surge of electrical energy to the starter motor for the purpose of starting the engine and to the ignition system while the engine is being started.

2. It supplies electricity for the accessories such as the radio, tape deck, heater and lights when the engine is not running and the ignition switch is in the “OFF” or the “Accessory” position.

3. It supplies additional electricity for the accessories while the engine is running when the output of the alternator is exceeded by the various extra accessories. If the output of the alternator is abnormally low the battery will supply the needed energy to operate the component or accessory.

4. The battery stabilizes voltage in the electrical system. Maximum operation of the ignition system and any other electrically operated device is hampered by a damaged, shorted, weak or even an undercharged battery. Many accessories operating at once demands that a battery be in peak condition to supply the demand of all components.


Not too long ago, batteries came with filler caps and needed to be periodically checked to make sure the distilled water level was high enough to sustain a proper electrolyte level. Today the sealed battery, or what is referred to as “maintenance free” or “freedom” battery, is much more common. Sealed batteries have a different chemistry and construction which provides some advantages over the older model. For one thing, sealed batteries don't have to be checked and adjusted for low battery water. The battery is completely sealed except for two small vent holes on the side. These vent holes allow minute amounts of gas to escape, a necessary breathing device. But the special chemistry composition inside the battery reduces the production of gas to such an extremely small amount that it's nearly undetectable at normal charging voltages.

The sealed battery is almost impervious to the damaging effects of overcharge. The terminals are tightly sealed to minimize leakage, and on many models you can find a charge indicator, or an electronic eye that shows the battery’s present state of charge. As an added bonus, compared to an older make or conventional battery in which performance decreases steadily with age, the sealed battery delivers more available power at any time during its life. The sealed battery has a reduced tendency to self-discharge as compared to the older conventional battery.


Damage to a battery occurs frequently when a car stalls and panicked owners keep desperately turning the key to start the engine. Trying to start a vehicle for overly long periods (over 30 seconds) causes extreme amperage draw and, in some cases, can damage the battery cables and melt their protective insulation. It can also warp and damage the positive and negative plates. Such persistent starting can also damage the windings of the starter motor. It is best to attempt starting in short intervals to allow the electrical circuits to cool somewhat and recover before trying to restart. A hard-starting engine should not be confused with a bad battery or starter, particularly if the cranking speed of the starter is fast and the battery energy is at maximum. A poorly tuned engine can also be the cause.


There are many reasons why a battery can discharge or appear to be defective. It is all too easy to just blame the battery and have it replaced. As a preliminary test, turn on your headlights. Normally, a discharged battery can be seen in the relative brightness of the head lights. Dim headlights likely indicate a weak or partially discharged battery.

However, there are many other factors that could be responsible for the symptoms of a dead battery. Your mechanic should know these symptoms as should you. Don’t be talked into purchasing a battery on the spot. The following are some of the common conditions that could discharge a good battery:

1. Leaving the headlights in the “ON” position or the car doors ajar, which would leave the dome light on, would discharge the battery over a short period of time. Leaving a tape deck or radio on, that was hooked directly to a positive lead instead of the fuse block, would also drain the battery.

2. The continued and excessive use of vehicle accessories with the engine not running could cause a direct drain on the battery. The more accessories used, the larger the energy draw.

3. A broken or worn alternator belt. This condition would prevent the alternator from recharging the battery when the engine is running.

4. The improper installation of aftermarket accessories: fog lights, stereos, etc. They may have been wired to a circuit to a point where it overloads and shorts out, producing excessive drain.

5. A battery that has corroded inner plates or a battery case that has been physically damaged allowing battery acid to escape.

6. Loose or corroded battery terminal connections or damaged battery cables. Extremely long battery cables can, over an extended period, put an additional load on the battery and build up resistance.

7. Low alternator output or unusually low RPM’s at engine idle.

8. High resistance in the charging circuit caused by other loose electrical connections.

9. A defective starter that draws more amperage than normal.

10. A battery that has been sitting for a long period in an unattended vehicle—which could be from several weeks to several months.

Troubleshooting—Most repair facilities can test the condition of your battery. The service is usually free of charge, or should be, and while they are at it they often check the charging system to determine if the alternator is at fault. If they don’t, request that they do before purchasing a new battery.

With a non-sealed battery a hydrometer can be used to measure the specific gravity of the electrolyte in each cell. There are many types of hydrometers available, the least expensive consisting of a glass tube, a rubber bulb at the end of the tube and a floating device within the tube. Simply sucking up some of the electrolyte from each cell and examining the position of the float can tell you what condition your battery is in. The increments on the tube might be colored sections that denote words such as “no charge,” “poor,” “fair,” “good,” and “full charge.” Note that the car does not have to be running while a hydrometer check is being made.

A sealed or maintenance-free battery is commonly load tested, with a box-like mechanism that has two leads connected to it, one positive and the other negative. The mechanic hooks up the test leads to the appropriate positive and negative poles on the battery.

He pushes a button which simulates a cranking load (putting the battery under normal strain) and counts down a specific time interval. He releases the button and watches a dial indicator noting how fast the needle is recovering from the load shock and where the needle eventually ends up on the dial: poor, good, full charge, etc. This is a perfect way to simulate a start condition without having to run the engine.


Load testing is a highly accurate test if properly and honestly used. But the battery being tested must have a full charge via a battery charger before the test is performed.

Most customers come in for battery checks because the car wouldn’t start and suspect a dead battery is the reason. Often, they jump-start the car to get it in to the repair shop. If the engine is shut off and the mechanic immediately performs a load test, the battery will almost always fail, and the customer will be sold a new battery. When an undercharged battery is put under a load it drops in energy quicker and ends up in the “fail” zone according to the dial indicator. The mechanic will demonstrate this to you, and then sell you a $60 battery. To protect yourself, always insist that the battery be fully charged before such a testis made. This would insure that your real problem was not some minor misfortune, like leaving the lights on, or the radio playing too long with the engine not running.

Charging—There are two separate methods of recharging batteries which differ in the time or rate of the charge. Slow charging is the best and only method of completely charging a battery to its maximum capacity. Slow charging is safe and can be used under almost any condition provided the electrolyte level is sufficient and the condition of the battery is good (good cells). The normal charging rate is about 5 amperes, sometimes a bit more. A fully charged battery is in evidence when all cell specific gravities don't increase when checked at three one-hour intervals and all cells are gassing freely. Charging periods of up to 24 hours are not uncommon to completely re-saturate a battery but, realistically, from two to six hours is the more common practice.

The other method, known as a quick charge, is best for something like a roadside emergency, or to charge the battery for a load test. With a quick charge (much faster ampere rate) the battery isn’t fully charged back up to its maximum, but up to an acceptable level of charge for the purpose of starting the vehicle, whereupon the alternator can take over to get the battery back up to maximum. The quick charge poses problems if it's done with too high a rate. This may warp or mutate the interior battery plates. Quick charging is very hard on a battery and should not be used repeatedly as a remedy to replenish the battery’s charge. The possibility of battery explosion with a faulty battery under quick charge is a grim reality.

A fast charge takes anywhere from 15 minutes to an hour, and you shouldn’t be charged the same fee for both types. The extra time and the additional money spent for a slow charge is the preferred way to go. Don’t ever let mechanics fast charge your battery, unless you are in an extreme emergency.


When batteries are under a charge, highly explosive hydrogen and oxygen gases form in each battery cell. Some of this gas escapes through the vent holes in the plugs on top of the battery case and forms an explosive atmosphere surrounding the battery. This explosive gas lingers in or around the immediate vicinity of the battery, sometimes for hours after the battery has been charged. Sparks or flames can ignite this mixture and cause a dangerous battery explosion, spewing acid everywhere. So don’t smoke, or disconnect live circuits. Always shield your eyes when working around batteries, whether they are being charged or not.


If your battery needs to be replaced, be sure to choose one with the same capacity and voltage as the one supplied with the car. In some cases higher capacity rated batteries can be installed, depending on the manufacturer’s recommendation in your owner’s manual. If you don’t have an owner’s manual, the repair shop should have the information available.

Undersize—The use or purchase of an undersized (below rating) battery can result in poor performance and early failure.

For instance, in cold climates the cranking energy needed to start the engine increases with falling temperatures. Sub-zero temperatures can reduce a battery’s efficiency to 45% of its potential output and at the same time increase the energy required to turn over the engine by 3-1/2 times over normal weather starting conditions.

On the opposite end, hot weather can also place excessive energy loads on the battery. You’ll notice this when you attempt to start your car shortly after a hot engine has been turned off or stalls.


I don’t recommend installing a battery yourself if you don't know the correct procedure. Batteries are very dangerous to work with, especially for the layman who has never installed one, filled it with acid, and charged it. Installation should be free from a facility. However if you must “carry out” a battery and take it home to install in your vehicle, follow the guidelines outlined nearby under Installing It Yourself.

Oversize—Buying a battery of higher capacity, quality and rating is wise if you’ve installed a lot of accessories (mega stereo, telephone, radar detector, alarm, etc.) which all add up to extra load on a standard battery. Campers with extra clearance lights, tow packages that re quire additional wiring harnesses, high amp and watt stereos and other aftermarket accessories put more demand on a battery than it was originally designed for. Even when very heavy electrical loads are encountered, a higher output alternator that will supply additional charge at low speeds may be required to increase battery life and improve battery performance. The less demand put on a battery at any given time, the better chance the battery has in recovering without harm or permanent damage.


If you should have to replace the battery in your car yourself, there are a few logical steps—some do’s and don’ts. Careless installation of a new battery can ruin it as well as yourself. When removing the old battery, check the position of the positive and negative poles and size up its position in the battery tray with the profile of the new battery.

The replacement battery must be installed in the same position as the old one; sometimes the battery cables will not reach the terminals if the pole positions are reversed.

Always remove the negative ground cable first by using an open end wrench to loosen the clamp (some terminals must be spread by the use of a screwdriver). If the nut is very tight, use one wrench on the head of the bolt and the other on the nut to avoid straining and possibly cracking the top of the cover. Using box-end wrenches works best since they don’t have a tendency to strip the nuts.

Special battery pliers are available in stores and can be used on bolts and nuts that have been damaged. A pair of vise grips might be needed to remove a stubborn nut and bolt.

If a battery cable terminal is corroded to the post, don't try to loosen it by hammering or by resting a tool on the battery and prying upwards—either method can break the battery cover or uproot the terminal shaft.


The electrolyte solution in the battery is a strong and very dangerous acid. It is extremely harmful to the eyes, skin, arid clothing. If acid contacts any part of the body it should be flushed immediately with water for a period of not less than 15 minutes. If acid is accidentally swallowed, a person should drink large quantities of milk or water, followed by Milk of Magnesia, a beaten raw egg or vegetable oil. Then contact a physician immediately.

If you must, use a screw type terminal puller (which can be bought in auto parts stores), or spread the cable terminals slightly with a screw driver then lift up.

Clean any corrosion or acid build-up on the cables, battery case or hold-downs, and inspect them to make sure that they are operating properly, particularly, the hold-downs.

Baking soda, when used with warm water and a stiff cleaning brush, will do an adequate job of neutralizing corrosion and battery acid.

Install the battery in position making sure it sits level. Then tighten the hold-downs a little at a time, alternately, to avoid distorting and breaking the battery cover. Clean the battery posts bright with sand paper or use a wire brush. Don’t hammer the terminals down on the new battery posts; spread them if necessary, and install the starter (positive) cable first and the negative cable (ground) cable last. Tighten the terminal bolts after making sure the cables are not overly stretched or rub against the hold-down or battery cover.

The hold-downs should be snug enough to prevent the battery from bouncing in its frame. Paint or grease (white grease or acid-proof paint) the hold-downs after you have installed them onto the new battery. A small piece of felt under the terminals will help serve as an acid and moisture sponge.


Be very careful when connecting or disconnecting jumper (booster) leads or cable clamps from battery chargers. Make sure that live (working) circuits are disconnected before connecting or disconnecting the booster leads or cable clamps. Faulty connections on the jumper or booster wire (torn or worn insulation) are the most common cause for battery explosions; this is due to electrical arcing. Jumping sparks can ignite a battery and cause a terrific explosion, sending plastic battery material flying like missiles.

For drivers who find themselves with a stalled or dead battery some precautions should be followed to insure a safe and successful jump start. They are:

1. First, be sure that the ignition key is in the off position and all the accessories and lights are off.

2. Shield your eyes if possible. Use goggles or similar eye protection. Sun glasses can serve as a substitute.

3. Connect the jumper cables from the positive (+) battery terminal of the discharged battery to the positive terminal of the vehicle used as the jumper.

4. Connect one end of the other cable to the negative terminal of the good battery.

5. Connect one end of the other cable to an engine bolt head or similar good ground contact on the vehicle being started— not to the dead battery itself.

6. Start discharged vehicle.

7. Carefully remove jumper cables one at a time while discharged vehicle is running, making sure not to touch the cable ends together or to the surface of either car.


A starter has a pretty tough job. Its job is to spin the flywheel, a round disc with teeth bolted to the crankshaft of your engine. When the starter spins the flywheel, the engine turns over. One of the most common errors on the part of both customers and inexperienced mechanics is to assume a starting problem is caused by a bad battery when in fact it's the starter motor. A worn starter motor, after continued use, will crank slower or turn with more difficulty. This draws additional energy from the battery, wearing it down to a discharged condition.

Continually trying to restart a vehicle with a worn starter, or jumping a vehicle with a worn starter motor, is likely to damage the battery internally due to overload and heat.

If a starter motor still cranks slowly with a booster jump it's an indication that the starter, and not the battery, is at fault. Attempting to start vehicles with worn starter motors does not always ruin the battery. After a new starter is installed, usually the battery can be slow charged back to its original optimum condition.

Headlights that are bright coupled with a slow cranking starter usually indicates a problem with the starter and not the battery.

It is needless to explain the inner workings of the starter because starters aren’t replaced piecemeal, you have to purchase the whole she-bang. They are seldom rebuilt at customer request, and when they are reconditioned, it's usually done by a machine shop that performs this work in the interest of reselling the rebuilt products back to the retail and parts outlets. That’s why there is often a core exchange policy, meaning you have to give the facility your old starter in order to get a new one, when a new starter is replaced in your vehicle.


Since the starter motor is such an essential part of the electrical system, and because it's too easy to fall prey to the mechanic’s recommendation that it be replaced, you should be familiar with some symptoms of failure. Some of the symptoms are progressive and give warning before there is a complete component failure in the starter motor. With the following we will examine some of the most common starter and solenoid problems. If your mechanic performs a thorough check and comes up with one of these reasons, then chances are he’s on the up and up.

Nothing Happens When Key Is Turned—This could mean several things. It could mean the battery is defective or undercharged, or it might be just that the cables are heavily corroded or loose at the terminal. Open the hood of your car and check the cables. If they are corroded, get some baking soda mixed with warm water and a brush, then pour it on the corroded battery terminal and brush off the corrosion. Be careful! The corroded goo is acid and will burn your skin. Don’t touch it!

Some cars are equipped with fusible links, or fuses installed in the fuse blocks that burn out when abnormal current is encountered; they are cheap protective devices designed to guard against more expensive damage to the other major components. So the problem could be a burned fuse. On the other hand, it could be a loose or unadjusted neutral safety switch. This switch is sometimes located in the shifting lever console of a car equipped with an automatic transmission, or it's connected to the clutch linkage in manual transmission cars. In other words, it prevents you from starting the car when it's in gear. Auto transmissions must be in “Park” or “Neutral” and the clutch must be depressed to the floor or the gear lever set in neutral in a manual transmission in order for the car to start. This switch occasionally malfunctions.

Speaking of switches, the contacts in your ignition switch can also become worn.

You Hear A Click—This could also mean a discharged or defective battery or cables, or loose or defective wiring at the starter. The solenoid could also be worn. The starter motor might also be frozen.

Slow Cranking Starter—This could be an overheated vehicle. More amps are required to start a hot engine and this would slow the rotational speed of the starter motor. Again, the battery might be undercharged or defective, or the battery-to-engine ground could be loose. Finally, the ignition timing could be off.

Starter Grinds or Clanks—This could mean the drive gear in the starter is damaged, you hope, because the alternative is that the teeth on the flywheel, located between the engine and the transmission, are worn. Replacing a flywheel falls into the category of major, expensive repair. Of course, the bearings or bushings in the starter could also be worn, allowing excess play. Finally, it could be a simple case of loose or broken starter mounting bolts, which would throw the alignment off between the gears of the starter and flywheel.

If your car develops any of these symptoms, go to a mechanic and explain them to him thoroughly, using the list of possibilities as a guideline. Because of the complexity of this system, the dealership is your best bet. The dealership will most likely charge you a minimal shop charge of .5 or a half-hour labor for troubleshooting electrical problems. However, the fee is usually credited toward the total bill if you have them do the repair.


A seemingly worn or defective starter can be the direct result of another component problem, i.e., a battery that has a dead or shorted cell, or the alternator can be faulty, etc. What you want to avoid is a mechanic who does not use the proper volt/ammeter gauges, and who instead determines the worthiness of your starting and charging circuit parts by looking at them or listening to them. It is all fine and well for a mechanic to tell you, “Yep, sure sounds like the starter, you need a new one. “ If you go ahead and replace it on that premise, then you deserve to be taken. The days of “touch, feel, and hear” are over, and any mechanic who does not know the rudimentary basics of electrical function, or the application of electrical testing devices or procedure, shouldn’t be doing the work in the first place.

What The Mechanic Should Do—The first thing that a mechanic should do when diagnosing a starter problem is to examine the present condition of the battery with the load or hydrometer tests previously described. Remember to have him fully charge it prior to these tests if the battery is dead.

The charging circuit should be checked out next to see if the alternator is supplying enough charging voltage to the battery. Once the battery and alternator have passed their respective tests and eliminated as culprits, the starter should be tested for its condition and operability. This is assuming that the other fuse and wiring circuits have been ruled out.

By the use of a volt/ammeter testing unit, the mechanic can check the starter directly and determine through a gauge reading how many amps the starter is requiring to perform its function. If he gives you a reading and tells you it’s below that recommended by the manufacturer, ask to see that in the manual. A starter requiring more than its original amp rating load is worn or defective. In addition to the above test, several other procedures are recommended, i.e., a field ground circuit test, a starter no-load test, a starter solenoid test and many others. Without these tests and diagnostic gauges and meters, accuracy can't be attained in discovering the true operability of the starting and charging circuit. If your mechanic doesn’t perform any of these tests, and still recommends a new starter, it's possible that you are being set-up for a quick sale.


If your starter has been positively diagnosed as defective through the use of proper testing procedures, and if a complete starting and charging circuit evaluation was performed, then you can start thinking about replacing the starter. It’s up to you if you want a new (expensive) or rebuilt (inexpensive) replacement starter. My advice is to go with a new unit, because the starter is used frequently and has to bear the strain of turning over the engine. Of course, if you’re strapped for funds, or perhaps if you don’t value your car all that much, then go with the rebuilt unit. But personally I have found that rebuilt or reconditioned starters are substandard as far as quality, operation and durability are concerned.

Core Exchange—An auto repair facility usually requires the ex change of your old starter for the new one, which will get you a discount when you trade it in. Make sure you get this deal. Remember also that solenoids are commonly sold as a package deal with a starter (and rightly so), as the solenoid is considered to be part of the core swap as well. Make sure they give you the solenoid.

Getting Your Own Part—Find a special deal on a starter? Fine. But they are difficult to install by yourself unless you’re pretty handy with tools. Starters aren’t a bonus or commission job, so mechanics don’t benefit. However, the shop usually realizes a large profit by overcharging you for the starters when they order it from another facility. That’s why they like to sell them to you directly, and that’s why if you ask them to install yours, they will probably refuse. Before you go rushing off to purchase a starter from somewhere else (and this goes for most other parts purchases) call the repair shop and tell them what you’re doing and ask if they’ll install it. That way, you won’t be stuck with a starter that sits in your trunk.


There are many different makes of alternators, but most fall into two basic designs—the standard alternator with a separate regulator and the integrated alternator/regulator single-piece unit. The primary function of the alternator is to recharge the battery and supply electricity to all other systems that require it, only when the engine is running.


When the charging system goes to hell, the idiot light usually comes on in the dash to tell you that the alternator, regulator, or charging circuit wiring is worn or damaged.

The Belt—If the alternator belt is loose or has simply snapped, it won’t charge the battery. In either case it's a relatively simple chore to tighten the belt or purchase a new one. Even if the belt is intact and appears to be tight, grasping the alternator pulley impeller and trying to turn it will tell you if the belt is loose or slipping.

The belt is adjusted by loosening the alternator bracket and shifting the alternator housing, applying tension on the belt. The belt should be snug and not overly tightened. Make sure you check by looking into the engine compartment for this problem, especially when told by a mechanic that your alternator is frozen and you need a new one. A belt only costs about $7, about 12 times less than an alternator.

Low Idle—If the red dash light comes on or is perceivably dim just after you start the car, it's probably due to the decreased rpm’s in the engine (low idle). If the red dash light does not disappear after the car is warmed up but does after the accelerator is pushed, it means that the idle speed setting on the carburetor is probably set too low, and this can be remedied by a carburetor adjustment.

These tests are rudimentary and not designed to establish the exact cause of the discharge condition. They are proof enough to know that a definite discharge condition exists. Any vehicle exhibiting such a condition should be taken into a repair facility where the exact and proper diagnosis can be made. The mechanic will make the necessary tests using a volt/ammeter to determine just what the low and high speed voltage output is of the alternator.


Some parts on some alternators are replaced rather easily. Brushes, for example, are sometimes accessible from the outside of the alternator and cost less than $10 to replace. A mechanic can pop them out, see if they are worn, then put in a new set.

But generally, it's common practice to replace the entire unit. The reason is because the time and labor involved in rebuilding an alternator can equal or exceed the cost of a new one. Like batteries and starters, alternators have a core value and many shops require your old alternator in exchange for a new or rebuilt unit. Unlike starters, a rebuilt alternator is generally adequate, so you don’t have to spring for a new one.


If your major charging circuit components are checking out and you still have a discharge condition, the problem might lie in the wiring harness, fuse block, or other related wiring circuit. The only facility that does a fairly decent job of troubleshooting a wiring short or other systems fault is a dealership. Most other repair facilities don't have the time, skill and specific wiring diagrams to trace down an elusive wiring problem. Accurate and quick troubleshooting is dependent on the skill and training of the technician, and that's why the dealership is the best bet. Some dealerships may even have an electrical specialist. A dealership technician is more apt to find the problem faster and have the necessary manuals and tools to do the repair work.


  • It is true that the cost from a dealership will be higher, but that cost could be superseded by another facility that does not know how to handle the problem but instead attempts the repairs, fails, tries again and never succeeds in finding the fault.
  • The “maintenance free” battery has many advantages over the non-sealed battery; it holds a charge longer and can withstand prolonged high energy demands, and often comes with a longer warranty. The higher price is worth it.
  • A higher rating capacity battery is advised if the energy demands for a vehicle surpass normal operation.
  • This includes additional aftermarket accessories that have been installed on the vehicle which drive the energy demand up. (Consult owner’s manual for battery limitations).
  • A battery can discharge if an accessory is left on, by a broken alternator belt, by physical damage, loose or corroded cables, low alternator output, high resistance in the charging circuit, a defective starter and sitting for very long periods without activity.
  • Purchasing an undersized (below rating) battery can result in poor performance and early failure.
  • Extremely hot or cold conditions can reduce a battery’s effectiveness by up to 45%.
  • Oversized (above capacity rating) batteries should be considered if the vehicle is permanently equipped with numerous aftermarket accessories.
  • Overcranking should be avoided at all times. Extended attempts to start the engine for more than 30 seconds at a time could result in permanent battery or starter damage. Wait and allow for cool down intervals.
  • Battery oversell is a reality. It happens when a mechanic does not follow recommended troubleshooting procedures when checking out the entire starting and charging system. Load tests should only be performed on fully charged batteries. Hydrometer tests can be performed on non-sealed batteries, however this battery should also be fully charged before the test.
  • Slow charging is the best way to bring a battery back up to normal condition. Fast charging, especially on a used or older battery, can weaken or ruin it.
  • Use extreme caution when installing your own battery. Remember that most repair facilities provide this service free with a battery purchase. If you must install a battery yourself reread the precautions in this section.
  • Starter motors can be internally damaged by prolonged cranking just like batteries. Allow sufficient cool down periods between starting attempts.
  • The mechanic should check out the battery and charging system when diagnosing a faulty starter.
  • Headlights that are bright coupled with a slow cranking starter usually indicate a problem with the starter and not the battery.
  • Overheated engines, loose starter cables, broken engine parts and discharged batteries can appear to look like a starter problem, when in fact they are not. A bad ignition switch, blown starting circuit fuse, defective fuse block, or misaligned neutral safety switch are also unrelated to a bad starter.
  • High wire resistance and improperly set ignition timing can cause a good starter to crank slowly.
  • If the starter keeps running after the key is released, it’s probably a defective ignition switch or solenoid.
  • An improperly tuned engine can cause hard starting and should not be mistaken for a bad starter.
  • Purchasing a new starter is preferred over a rebuilt one. Remember that you have a choice.
  • If you have a carry-in starter (your own), you can ask the management if they will install it for you for a labor only cost. Some shops do, others don’t.
  • Most alternators today are integrated; both the alternator and regulator are one piece units.
  • The alternator/regulator maintains appropriate cur rent to the battery and other systems that require it during engine running.
  • Abnormal readings on a dash amp meter (very high and low) and the red warning light, are the most obvious devices by which a person can tell if he has a discharge condition in the alternator.
  • Slipping or broken belts, low idle, loose harness wires and a defective regulator device, can all cause discharge conditions.
  • A discharging alternator/regulator can eventually lead to a no-start condition. The battery needs optimum current from the alternator to supply sufficient energy to the starter motor to turn the engine.
  • Alternators, starters and generators (if so equipped), have a core value with most repair shops. If you retain your old part chances are the price of a new or rebuilt one will be higher because the shop wants the old part in trade.
Very difficult wiring shorts are best checked out and repaired by a dealership. Typical R and R shops are not equipped to handle this type of technical repair.

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