Brake/Battery Warning Lights On Together

[CamryMan19]

I'm trying to help out a good friend here. He's got a '91 Corolla DX wagon with around 175,000 miles on it. Runs okay but recently, his brake and battery warning lights have been on steady and occasionally they'll flicker but most of the time, they stay on. The e-brake is not engaged, brake fluid is fine, and the battery is brand new. What's the deal? Any help is greatly appreciated.

[karazy]

As long as the charging system light is on, no other lights can be trusted. A low voltage situation can cause false signals. You should check the alternator and the battery, but check the connections first. They may not have been tightened properly on the new install. New batteries can be defective. I always recommend checking the alt, to make sure it wasn't the cause of the battery failure.

[Drifta89]

I agree. Check the alternator. My dad's 90 wagon had the same issue. His car ran fine with the warning lights displayed for a while and then it died on my brother. Turned out it was a bad alternator.

[CamryMan19]

Thanks guys.

[REN69]

We had this discussion a few times before.. a search would've netted you the same answer. Brake + battery light = Alternator or battery is dying.

Get the battery checked for charge hold, if it passes then your alternator is gone.

Another simple test, take the positive cable off the battery while the car runs, if the car shuts off then the alternator is dying, if the alternator is fine, it should be able to keep the car running.

[CamryMan19]

They tried unplugging the negative terminal while the engine idled and boom...dead as a doorknob. Alternator has been replaced and runs fine. Thanks again.