Electrical System Repairs

Your car both produces and consumes power. Part of the engine’s power is used to produce electrical power, which then is consumed by the computers, spark plugs, lights, radio, and other paraphernalia. The battery is the power storage room (yes, it’s a small room). Repairing or replacing these components is what this article is about. Your car’s charging system includes the alternator, voltage regulator, battery, cables, wires, and fuses. (Don’t sweat it yet if you don’t recall what these are; I describe each of them later in the Page.) Some alternators have the voltage regulator built into them; others require a separate component to regulate the alternator’s voltage output. Some of us with geriatric cars have generators instead of alternators. Same difference. If troubleshooting says you need to repair electrical components, this article will show you how. Most components in the charging and electrical system of your car are replaced rather than repaired. In fact, they are another commodity item. You can find them on the shelf of most auto parts stores or through mail-order suppliers and replace them yourself. You’ll be able to make these repairs with your car care toolbox.

Car Electrical System

When the Automotive Power Goes Out

I know you’ve been waiting anxiously for these. Here are a few useful tips for troubleshooting charging and electrical systems. Solutions are offered later in this article.

  • If the battery tests okay but won’t hold a charge, make sure the alternator drivebelt is adjusted tight. If the drivebelt is okay, test the voltage regulator using a volt-ohmmeter.
  • If turn signals work only on one side, check the bulb and wiring on the side that isn’t working. If they don’t work at all, check the fuse.
  • If you suspect that your car’s battery is weak, pull your car up to a garage door or other wall, turn off the engine, and turn the headlights on for a moment. If they are bright, the battery and voltage regulator are okay. If they are dim but brighten after you start the engine, the battery is bad. If they are bright but the engine turns slowly when you try to start it again, the starter is bad.

Energize Me

A car battery is an electrical storage device. It receives electricity from the alternator/ regulator and passes it on to other electrical components on demand. As the battery’s electricity is used up, it is replaced. Problems occur when a battery isn’t strong enough to keep a charge because the electrolyte is weak. This typically occurs a few days after the warranty expires.

Electrical System

To replace a battery, follow these steps:

  1. Find your car’s battery. It’s usually under the hood and typically on the passenger’s side of the car.
  2. Disconnect the cable from the negative side of the battery first and then the positive side.
  3. Remove the hold-down clamp or frame that keeps the battery in place. Typically, this means removing nuts from the end of two long bolts. Grasp the bolts as you loosen the nuts, making sure the released bolts don’t fall out of reach.
  4. Use a battery strap (from the auto parts store) attached to the two terminals to lift and remove the HEAVY battery. Set it aside for a moment.
  5. Inspect the battery tray for corrosion and damage. If the tray is rusted or damaged, replace it. Wearing rubber gloves, clean the battery with baking soda and water to neutralize the battery acids.
  6. Test the battery or have it tested to make sure it will hold a charge. If it will, recharge the battery or have it recharged by a mechanic. If it won’t, replace the battery with one of the same voltage, size, amperage rating, and coldcranking rating. Consider replacing the battery cables at the same time.
  7. Reinstall the battery, hold-down clamp, positive cable, and then negative cable.
  8. Lift your right hand over your head, bend your elbow to 120°, and then move your wrist repeatedly, patting yourself on the back. You done good.

Your Battery on Cable

A more expensive battery can be worth the extra expense. A 60month battery is built to hold a charge longer than a 48-month battery. So is a 60-month battery worth the extra money? Yes, it is-if you plan on keeping your car that long. If you plan to sell your car in the next year, a 36- or 48-month battery will do just fine at less cost. Your car’s battery produces and stores direct current (DC) by converting chemical energy into electrical energy. Electrolyte is the dietetic version of Electro. It’s also the sulfuric acid and water solution within a car battery that produces electricity.

Electrical System

The battery cables playa vital part in delivering electricity to and from the car’s battery. Battery cables are simply heavy-duty coated wires withterminals on the ends to make attaching them to the battery and other components easier. So what can go wrong with battery cables? They can become corroded by the electrochemical process that’s going on inside the battery. Corrosion is a buildup of powdery

substance on the cable ends. The ends can also be damaged by mishandling or become brittle with age. Unfortunately, I understand that all too well.

To replace your battery cables, follow these steps:

  1. Find your car’s battery. It’s under the hood and typically on the passenger’s side of the car. There are two cables attached to two terminals on the top or side of the battery. One is probably red and the other black.
  2. Disconnect the cable from the negative side of the battery and then the positive side. The negative cable is usually black and smaller than the red, positive cable.
  3. Disconnect the cables at the other end. The negative ground cable (usually the black one) is probably connected to the engine. The positive cable (red) is probably connected to the starter solenoid.
  4. Inspect the cable wire and ends for damage. Even if you can’t see it, there might be damage to the wires within the cable, reducing the flow of electricity through it. Battery cables are just a few dollars each, so replace them every few years whether or not you can see damage. The easiest time to replace cables is when you replace the battery, every four or five years.
  5. To find replacement cables, clean the old cables and take them to your favorite auto parts retailer for an exact match. You want the new ones to match the old ones in length, circumference, and ends. If you have a choice, spend a couple of extra bucks and buy ones with better quality wires to transport electricity more easily. Cheap is cheap. Pick up some battery terminal corrosion inhibitor (or petroleum jelly) while you’re at the store-and a candy bar for me.
  6. Reinstall the ends of the cables to the ground and the starter solenoid or wherever they came from, applying corrosion inhibitor to the bolt threads.
  7. Apply corrosion inhibitor to the positive battery terminal. Reinstall the positive (red) cable to the positive terminal on the battery.
  8. Apply corrosion inhibitor to the negative battery terminal. Reinstall the negative (black) cable to the negative terminal on the battery.

What to Do When You Can’t Charge Any More

An alternator produces electricity from a car’s engine. If your car’s battery is in good condition, but isn’t getting recharged, the charging system may be the culprit.

Car Electrical System

An alternator should give you at least 50,000 miles of service, and up to twice as much. Before you replace an alternator, check its drivebelt and pulley to make sure they aren’t the cause of the problem.

To test and replace an alternator, follow these steps:

  1. To test the charging system’s fuse, first locate the fuse by using the car’s service manual. It may be a fuse box or it could be on the wire between the starter solenoid and the alternator. Make sure the engine and ignition are off. Use an ohmmeter, placing one probe on one side of the fuse or wire and one on the other. If the fuse or wire has infinite resistance (1), the circuit is open and the fuse should be replaced.
  2. To test the alternator, refer to the car’s service manual for instructions on how to do so without removing the alternator from the car. One way of testing the system is by checking the battery’s voltage with a volt-ohmmeter (VoM). With the engine off, the battery should give a reading of about 12 volts. With the engine on, the battery should give a reading of 14-15 volts on the YOM. If it registers lower, replace the alternator. If it’s more than 15 volts, replace the voltage regulator.
  3. To replace the alternator, first disconnect the cable from the negative terminal of the battery. Then identify and remove all wires from the alternator. Loosen the alternator adjusting bolt, and then remove the drive belt. Remove the alternator from the adjusting bracket and the engine. Replace the alternator with one of the exact same size and rating.
  4. When done, test the alternator to make sure it’s doing its job. If not, sell your car and take the bus.

Regulating Those Volts

The voltage regulator plays an important role in your car’s charging system: It manages the alternator’s output voltage. How can you tell if the regulator isn’t working as it should? By checking the voltage of the battery with the engine running. If the battery voltage is less than 12 volts or more than 15 volts, the regulator is probably not working. Although you can replace the regulator without replacing the alternator, you should consider doing both at once. Don’t forget to disconnect the negative battery terminal when working on your car’s electrical system, and be prepared to reenter auto alarm codes if necessary, after the battery cable is reattached.

Electrical System Repair

To replace a voltage regulator, follow these steps:

  1. Find the dam thing. Your car’s service manual helps you locate it. Otherwise, older cars have the voltage regulator mounted on the firewall or a cowl (a wheel cover inside the engine compartment), and newer ones use a solid state regulator installed on the front side of the alternator behind the pulley wheel.
  2. Loosen mounting screws and remove the regulator. Don’t attempt to repair it. Replace it.
  3. Take the regulator to your auto parts retailer along with model numbers from the alternator on which it was installed. Make sure the replacement is the same size, shape, and rating as the unit it’s replacing.
  4. Install the voltage regulator, making sure that all wires are connected correctly.
  5. When done, test the voltage regulator to make sure it’s working as it should. If it’s now working properly, you have just passed the “Regulating Those Volts” final exam.

Other Auto Electrical Devices to Play With

Many other electrical devices in your car can also go awry at the least convenient time. They include lights, instruments, controls, radio, clock, and wiring (see the figure illustrating this system). Most have two wires; some have more. You can easily test these devices by checking the circuit to make sure electricity has a closed path through it. A volt-ohmmeter (VOM) can measure either the voltage in a live circuit or the resistance in a dead circuit. A live circuit is simply one with electricity flowing through it (with the ignition on and/or the engine running), and a dead circuit is one without power applied to it. So how is a dead circuit measured? The ohmmeter applies a small amount of electricity to the circuit using internal batteries, and then measures the output to see whether any of it made it to the exit. If so, it’s a closed circuit; if not, it’s open. An ohmmeter can also measure how much resistance the signal faced trying to get to the exit. Resistance is measured in ohms; more ohms means more resistance.

To test continuity of an electrical device, follow these steps:

  1. Isolate the device by marking and removing any wires attached to it. You won’t keep it isolated long enough for it to get lonesome.
  2. Decide what ohmmeter reading you should be getting (open, closed, low resistance, or high resistance). The owner’s manual can help you determine the appropriate reading.
  3. Test the device using the ohmmeter. If the reading isn’t what it should be, replace the device or have it repaired. A tum signal light should be replaced, for example, but an analog clock often can be repaired.

To test voltage of an electrical device, follow these steps:

  1. Make sure the device has power coming to it: fuses okay, ignition on.
  2. Learn what volt-ohmmeter (VOM) reading you should be getting (2 volts, 12 volts, and so on). The owner’s manual may help. Otherwise, estimate output voltage by what the device is designed to do: Use voltage to do a task (lower output) or multiply voltage (higher output).
  3. Test the device using the YOM. If the reading isn’t what it should be, replace the device or have it repaired, as necessary.
  4. Use your experiences with a volt-ohmmeter to bore others.

Further Readings: