JJ Glo

What could be the cause of the car's battery light randomly turning on while driving the car? Sometimes it turns on for a couple of minutes, then it turns off.

I don't believe there's anything wrong with the battery because it can hold a charge over several days.

Would a dying alternator do this? Or could it be a problem with the cables?

mrz2207

You should test what your battery voltage is and how much voltage your alternator is putting out.

PROMETHEUS PRIME

Does it come on when the RPM's are higher?

JJ Glo

Well, it has turned on from just driving it in the city, so the RPM's aren't usually high, 1.5-2.3k maybe.

QATIM

I'm interested in an answer to this also. My light has been doing the same thing. I've had it looked at, coded the whole nine. It's throwing no codes. At my wits end.

PROMETHEUS PRIME

If the brushes on the alternator are weak at higher RPM's they separate and loose charging. That are the regulator is goin out. Either way it most likely is the alternator.

DRAGUL

I have had this happen in the past on a few of my work trucks. Light would randomly go on and off until the alternator crapped out, then it would stay on all the time.

Subbz

Same thing has been happening to me. I got the battery and the alternator checked out by my mechanic and they were both fine. My voltage never drops so I'm not quite sure what causes it. Anyone have a definitive answer to this?

ZeroTX

The light comes directly out of the alternator. I thought it was fine, because it was making like 13 volts almost, but evidently it needs to make a lot more than that. I bought a brand new generic alternator (new, not rebuilt) off eBay for like 80 bucks and it fixed it.

lizzyfan

Yep! Without question!!