blower motor

**04pontiac** · 11-11-2012

I have an 04 GT and a couple months back the blower quit. I pulled the blower motor and hooked up 12v to it. Replaced the resistor and it worked for awhile. Recently stopped working. Tested the power going to the fan. It is constantly 12v in all speeds. Even with key off. Fan doesn't work at all. What could be the problem?

**04pontiac** · 11-12-2012

No suggestions?

**Buggsy** · 11-12-2012

Long shot, but look for a clogged cabin filter. If it's plugged up bad enough, it'll make the motor work harder and harder till the resister pack burns out.

Supply independent 12v to the fan if you can. Double check the grounds too. If it doesn't spin up with a good ground and 12v, it's the blower.

As for a constant 12 volts, that's not surprising. The fan controller is probably inside and out of sight. That's the source voltage for higher amperage draw. The controller works like a relay and will regulate the fan. I'm not really sure on this car, but that's probably the resister pack in this case.

**04pontiac** · 11-12-2012

The cabin air filter can't be to bad because at highway speed air comes through it. Why would there be 12v to the fan at all times if it was the resistor?

**Buggsy** · 11-12-2012

I have never removed my blower motor, so I can't say anything for sure. Just guessing from what I've seen else where to help you if possible. This is what I mean though.
You should always have 12v to the resister pack. That is the supply voltage to run the fan. Other wires are the control lines, so I'm not saying you should have 12v everywhere. 12v on the out side of the resister pack is probably bad. It's just possible that it's not enough amperage to actually allow the blower to start. Unless, that is, the actual controller for the blower speed is in blower, or the dash. Then the resister pack is ok, and you need to trace that back. I keep a couple of ~14' ten gauge cables with alligator clips on them around for this. You can clip onto the battery and supply good power to the device to test. If you give it power and it spins up normally, it's usually the resister pack.

I've only seen one car that actually supplied the current for the blower from the controls in the dash. I replaced the controls in my sister's Lumina twice because they melted. Most other cars use vacuum switches or a resister pack type of setup, and power comes directly from the fuse.

**04pontiac** · 11-12-2012

Is there a way to test the resistor without just replacing it?

**Ophidia** · 11-12-2012

I had that happen on my car twice before I found this:

http://ww2.justanswer.com/uploads/he...water_leak.pdf

Water goes right by the piss-poor seal between the windshield and cowl and floods/fries your resistor and blower motor. The part referenced in the TSB deflects the water so that can't happen anymore. It's a cheap part (might have even been less than 10 bucks) and like a 15 minute job.

If you already have it, then I dunno.

**Buggsy** · 11-12-2012

Originally Posted by Ophidia

I had that happen on my car twice before I found this:

http://ww2.justanswer.com/uploads/he...water_leak.pdf

Water goes right by the piss-poor seal between the windshield and cowl and floods/fries your resistor and blower motor. The part referenced in the TSB deflects the water so that can't happen anymore. It's a cheap part (might have even been less than 10 bucks) and like a 15 minute job.

If you already have it, then I dunno.

Thanks for that link. Related question. I replaced the cabin air filter for my grandma and found this short 12" piece of foam laying on top of the filter. I went back and took my car apart and don't have it. I tried fitting it into places around and under the cowl, but couldn't find the place it belonged. Now I see something like it in that TSB, but It didn't really fit in that spot. Anyone ever see something like that, or know where it should go? I just left it off because it didn't fit anywhere that didn't massively distort the cowl.