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What does the alternator relay do?

What does the alternator relay do?

An alternator relay can be set up to divert power from a starting battery to another DC power source, sometimes called a house battery. On some cars and trucks, the alternator relay switches power to the alternator only when another circuit, like the ignition circuit, is live.

Why does the battery light come on after the alternator is replaced?

This would make the Battery Light come on. It is also possible that there is a problem with the fusible link or the alternator fuse for the charging system.

What was the problem with my alternator going out?

I was thinking that the problem was probably the alternator and as I was trying to get to my house the instruments began to go out. First the tach, then the speedometer, and then the accelerator pedal was unresponsive. I was able to limp for a little while, but it eventually totally quit.

What happens to power steering after an alternator is replaced?

Usually when brakes pads are replaced and the rotors surfaced, it may make the brakes feel stiff for a while until they wear in, but it shouldn’t impact the power steering at all. The only thing I could think of… Engine sludge?

What should the charge voltage be on an alternator?

Turn on the high beams for 10 seconds and then turn them off. Measure battery voltage across the battery posts with your DMM. You should get between 12.4 and 12.6V. This means your battery is fully charged. If you get a reading below 12.4V, charge the battery before continuing. 5b. Measure the Charging System’s No-Load Voltage

When does an alternator relay need to be replaced?

On some cars and trucks, the alternator relay switches power to the alternator only when another circuit, like the ignition circuit, is live. You’ll know the alternator relay needs to be replaced when there’s zero continuity from the alternator’s charging wire to the positive terminal on the vehicle’s battery.

What to do if your alternator is over charging the battery?

Ask an assistant to start the engine and hold engine speed at about 1500 RPM. Measure voltage across the battery with your DMM. You should get 0.5 to 2 volts higher than base voltage. If you are getting more than 2 volts above base voltage, most likely your alternator is over-charging the battery or the battery is faulty.

Why does the battery warning light come on after replacing the alternator?

A relatively common “side-effect” of replacing a battery and/or alternator in a car is to have the voltage (battery) warning light come on. This is especially true in late-model vehicles with their more sophisticated internal diagnostic systems.

Why does my alternator get higher than base voltage?

You should get 0.5 to 2 volts higher than base voltage. If you are getting more than 2 volts above base voltage, most likely your alternator is over-charging the battery or the battery is faulty. Other potential problems are a faulty voltage regulator or a problem in the charging system wiring.

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Ruth Doyle