Battery light on, brake light on, "blown bulb" light on, car runs fine? - Toyota Nation Forum : Toyota Car and Truck Forums

Rebound91 · 07-07-2009, 05:22 PM

I apologize if I missed this already written somewhere, but I searched for a bit and didn't really find anything.

When I started my car today (91 Camry, 2.0L, automatic, FWD), the battery light, the brake light, and the "blown bulb" light came on and stayed on. The car ran fine, the oil light wasn't on, and the check engine light wasn't on, so I carefully tried to drive it. It seemed fine. I tried shutting the car off and starting it again and the same thing happened. I made my usual 20-mile commute home with this happening and the car drove completely normal. I fumbled through the factory service manual and found nothing. What could this be??

nuron · 07-07-2009, 05:38 PM

Your alternator is on its way out.

Rebound91 · 07-07-2009, 06:10 PM

Grr... just went outside to check. 11.89V across the battery with the engine running. Dammit! Thanks for the suggestion.

UPDATE: A few hours later, I started the car up to move it. No lights! Pop the hood, bust out the multimeter and now I've got 13.40V with the engine running. I took the (+) lead off the top of the alternator and cleaned it, as well as the connector on the side. It seems to be working ok. We'll see how this one pans out.

Mike Gerber · 07-07-2009, 09:25 PM

The lights will probably return. When they do and you check again with the DVM it will probably read under 12 volts again. I agree with nuron. Time to replace the alternator.

Mike

ChevyToughRebel · 07-08-2009, 08:11 PM

Or if your alternator has replaceable brushes you can replace the brushes, I did that on my 89 camry and spent less than $10, working great for over a year now. It sounds like its going in and out, next time the lights come on you can tap the alternator and see if it starts to work again, if it does your brushes need to be replaced. Some people would prefer to replace the alternator over the brushes. If the commutator is too badly worn then you should replace the alternator, otherwise brushed usually do the trick.

primal · 07-14-2009, 12:32 AM

what are the brushes. how would you change them?

Rebound91 · 07-14-2009, 09:19 PM

The lights came back a few times, and I don't really have the time to deal with a dead battery or rebuilding the original alternator, not to mention I don't have $125 for a reman, so I tossed in a $25 junkyard alternator with 124k miles on it for now. I might look into replacing the brushes on this alternator (gotta love the factory service manual going into such extreme depth!). For now I'm good. At least this will buy me time to tear into my old alternator and see if it can be easily rescued. I don't want to spend much more on this car. In the past year, it's cost me a good amount of money just to keep it going.

ChevyToughRebel · 07-15-2009, 07:03 PM

The brushes are located inside the alternator obviously. I cant remember what all involved replacing them, but sometimes it requires some soldering and dismantling the alternator. They are little black carbon? pieces generally with braided wire coming off of them. They make contact with the commutator on the armature. The only problem with replacing brushes is that usually the commutator will have a "valley" worn in it over time and the new brushes will take some time to fully seat to this. Its best if you can have the commutator ground down especially if the valley is deap, but don't attempt this unless you have the proper equipment, aka a lathe or something. So unless you can have it properly reground then just put the new brushes in the way it is. Perhaps this is more of a temporary fix but it does work and can last a while depending on the condition of the other components of the alternator. My alternator that I replaced the brushes on a year ago just started acting up again, this time it will have to be replaced completely. Its just starting to burn up but is still working. Well worth a few bucks to have it last another year. Heat, battery condition, and charge load is a big factor in the life of an alternator as well, so 180'000 miles on an original alternator and weak battery isn't too bad but it couldn't have lasted forever. I will probably go to the wrecking yard this weekend for another alternator to rebuild or use for parts, thats just the kinda thing I like to do, is rebuild things.

~ Shane

Rebound91 · 07-15-2009, 08:32 PM

You're probably right about the brushes wearing a groove in the commutator. My boyfriend machines quite a bit, so I might just give it to him and he can take it apart and machine it down in the metal lathe at his work. I asked him about it and he says they're usually copper and will machine really easily.

202k miles on the original alternator... can't ask for much more than that. The original alternator on my boyfriend's Daytona went at 208k, so I guess all bets are off after 200k when it comes to alternators, haha.

Mike Gerber · 07-16-2009, 08:02 AM

You do need a lathe to ground the copper on the commutator, but then there are little groves that go horizontially accross that copper area. They need to be recut in to that area. That too takes a special piece of equipment that rebuilders have. Those grooves give the worn off carbon material from the brushes a place to go. That's why I recommend taking your old alternator to an auto electrical rebuilder in your area to get a rebuild, if you have the time. It costs about the same money and they usually do a better job of rebuilding these things than the typical mass rebuilders that the auto parts stores use, IMHO.

Mike