My step sons 94 Sunbird heat blower stopped working. At the same
time the anti-light came on and also the brake idiot light flashes.
I ran a direct power to the fan and it works. The 25 amp fuse is also good.
What should I check next??
I

Arggh! There's probably a common ground at fault but the brake warnings don't make sense to me. Hey - if you have a RED brake warning light that means biz and must be checked out at once!!!! If so that could just be low fluid in brake reservoir but just filling it is not enough. Find out why which could be brakes are worn low or a leak/pressure problem - or parking brake switch. Too important to ignore that and let's take on the blower when that's solved,

T
Tom Greenleaf - MetroWest Boston - USA
_________________________________________

http://www.autoacsystems.com/tomgreenleaf/

Thanks Tom....I will definately look into the brakes ASAP. Any idea where the grounds might be?
I think there is one near the Master cylinder from a blower moter schematic I saw. I just noticed
I said Anti-Light in my previous post. It should have said Anti-Lock light..........


(This post was edited by ebby69k on Jan 2, 2008, 8:40 AM)

Well I had my step son look at a few things and for some reason he decided to
check the fuse again. It was blown. It was not blown when I looked at it.
He put in a new fuse and everything seems fine. None of the idiot lights came on.
Thanks again Tom

Just the amber anti-lock warning light should mean it won't work as anti-lock (whatever problem) but by design should default to regular braking action. The RED brake light means real trouble and the possibility of no brakes - there's a difference worth noting there. If that one is not on the amber one you can deal with as you see necessary.


Everything electrical needs ground. You'll see that the battery neg/ground cable goes to the engine block. The whole rest of the body of the car needs to share that so they put ground straps where needed around the car. Things can work with them broken or not making a good connection sometimes. Blower motor is mounted in plastic so it needs to be grounded to the contiguous metal of the body which needs to connect to the engine block and back to battery to complete the loop.

You said you added 12v + to blower and it worked which suggests it does have ground there. This may not be the problem but with two things happening at the exact same time I was just thinking of what is needed for either that otherwise shouldn't be on the same circuit at all. You can add ground with an alligator clip jumper wire to items that are known to need to be grounded and if that changes things then hunt for why or in some cases you can just add another. Don't go around just poking every wire or thing - I meant things that are supposed to be ground. Test out fuses with a test light as they can appear good an not be.

I want you safe with the brakes first. There are other things that can screw up the blower motor,

T
Tom Greenleaf - MetroWest Boston - USA
_________________________________________

http://www.autoacsystems.com/tomgreenleaf/

Cool! I was delayed with my reply before I just read your findings,

T
Tom Greenleaf - MetroWest Boston - USA
_________________________________________

http://www.autoacsystems.com/tomgreenleaf/

Hi Tom

Welllll I just got a call from my stepson. He said the fuse blew again. Do you think maybe the
blower is drawing to much. He said it was working fine when he shut the car off. He started
it back up and it was not working. My guess is the fan was left in the on position.Thanks again.....
Dave


(This post was edited by ebby69k on Jan 3, 2008, 1:26 PM)

Hmmm? The fan being left on shouldn't blow the fuse so easily. I do that all the time and never have problems.

How long did it last when replaced? Just until the fan was left on but worked fine before that? If so it could be the blower drawing excessive current.

I'm not quite ready to suggest replacing it yet. I guess have a couple fuses handy and try assertively to shut down the fan each time and see if that helps or problem quits. Was going to suggest only using lower fan speeds but I think the way a resistor (used to reduce fan speed) uses the same amps at all speeds - not certain about that but it could be.

One more question: Is there any problem or noise with the fan noticed at all?

T
Tom Greenleaf - MetroWest Boston - USA
_________________________________________

http://www.autoacsystems.com/tomgreenleaf/

Talked to my stepson today. He says the fuse only blows when the fan is on and he
starts the car. If the fan is off it is fine. He did not say if there were any funny noises from the
fan. So for now I guess we make sure the fan is off. thanks again for your replies.

Dave

New update....Fan does not work and fuse is not blown......Put a new one in still does not work.
Hmmmmmm....My guess is bad fan,resistor, or short somewhere....LOL

Another update. While driving the car the fan switch was on but not working. All of
a sudden it came on and is now working.

I see this will be an epic thread at the site! It's still playing cat and mouse with us both. Just curious now - will the anti-lock light come on when the fuse that once blew is pulled? If so that really make a wiring short the likely problem.

The resistor shouldn't be able to heal. Generally when those are bad you still get the high speed fan. Fan motors get weak spots and can simply not work and those will usually start up with a tap on the body of the motor but don't usually blow fuses. The fan speed selector switch could be the problem.

I guess I'll wait to hear what happens when the fuse is pulled to make a guess as to what you might try next,

T
Tom Greenleaf - MetroWest Boston - USA
_________________________________________

http://www.autoacsystems.com/tomgreenleaf/

I had the same problem, the anti lock brake light on the dash and the blower are on the same fuse. My problem wasn't related to anti-lock brakes but with a problem in the AC Compressor clutch. Replaced and problem went away. Also check your fan blower, for problems. This is also a common cause, Good luck and happy electical hunting.