dlabrec

I have 91 Camery with 175k miles, the batter light, brake light and "light" light started coming on today while driving.

Is this a sign that the alternator is going bad?

Thanks

kcg795

Toyota's warning system for the alternator is weird. But that is a good sign. What do you mean by "light" light? On my Toyota Van, when the alternator is bad, it flashes the battery, brake, and radiator lights. Not sure why it doesn't just flash the battery light.

Mike Gerber

Yes it is.

You may want to test it out with a DVM (digital volt/ohmeter) to be certain, if you have access to one. With the car off, set the DVM to 20 volts DC. Now touch the 2 probes to the battery terminals. You should read about 12-1/4 volts. Now start the engine and do the same test. If the alternator is charging, it should now read 14-1/4 to 14.6 volts. Chances are you will just get battery voltage again, or a bit less. This is a simple test to identify a faulty alternator. Some auto parts stores will also test your alternator for free. Some will do it on the car, while others require you to take it off the car and bring it inside. Call around to a few stores near you. But it does sound like it's time for a replacement.

Mike

vicchang

The most common problem for an alternator is the carbon brush. The original normally last about 140k - 170k miles. When it worn out, the alternater will not have any output. The reman one costs $100 - $200.

If you are handy, you can take the old alternator apart and just replace the brushes. A pair of brushes cost under $5.00 in hardware store. Just make sure the size is right.