racosun

I've read through many threads here regarding my heater blower motor on my 92 Camaro RS, but have yet to find a problem that fit mine exactly. I'm very new to the Camaro repair game, so I know very little about the car. I do, however, have a Haynes Repair Manual handy, but it too doesn't quite explain how to fix my problem. Okay...

My heater fan won't work on ANY level whatsoever, but does have a mind of it's own and works fine when it feels like it. This can occur when I've been driving awhile, or when my wife slams the door because I've been driving too damn fast again. I was a moron and went out and bought a new heater blower motor before properly troubleshooting, hoping that the fix was as easy as the Haynes manual made it look. I unplugged everything from the blower motor and had one screw undone before I got cold feet and wondered if I was getting in over my head. After plugging everything back in and starting the car, the damn heater was once again feeling perky and working just fine. I thought that somehow I fixed it, but lo-and-behold it quits on me again, and goes back to it's on-again/off-again ways.

I'm guessing that this is an electrical wiring problem somewhere, since the heater blower motor obviously is not shot to hell or anything. I live in the Upper Peninsula of Michigan and since my '96 GMC Jimmy decided to die on me, I'm forced to drive this awesome yet awkward-on-ice beauty for the duration of the winter and would LOVE to have heat.

I apologize if this problem has already been addressed and solved, I just couldn't seem to find the fix anywhere. All help and advice is greatly appreciated!

paulo57509

There can only be a two issues with the problem you're having.

1. The blower motor is bad.

2. The wiring/switch/resistor to the blower motor is bad.

Unless the wiring in your car is hacked (like a lot of 3rd Gen wiring), I doubt this is your problem. I would try this to make sure.

1. Unplug the 12v and ground connectors that are attached to the blower motor.

2. Connect a volt meter to the 12v and ground connectors (wiring harness side).

3. Turn the ignition ON (you don't need to start the car.

4. Adjust to HEAT mode.

5. Observe the reading on the volt meter.

6. Move the fan speed switch to all positions. You should see voltage in varying amounts on the volt meter. If you don't see voltage, the problem is with the wiring.

If you do see voltage on the voltmeter, your problem is probably with the blower motor.

I've had blower motors work intermittently when their brushes start to get worn.

racosun

Thank you very much for your suggestions. I don't have the proper equiptment to test the wiring and whatnot at the moment, but do happen to have a spanking new blower motor sitting in my garage, so I'll swap that out and see if it works. If not, then I guess I'm on to replacing the other things you mentioned. Again, thanks...I'll post the outcome as soon as I'm finished.

racosun

When I took off the old blower motor, I reached in the motor compartment and found a whole LOT of this:

racosun

I dug in a little further, pulled out a few more good-sized handfuls of hay, and then stuck my household vacuum cleaner in there to hopefully get out the rest. I installed the new blower motor and tried out the heater. This time I got full-blast defrost action, and that is all. In fact, it's full-blown defrost no matter which setting I use. What happened? Did Advance Auto give me the wrong blower motor? Did I forget to hook something up, or hook something up wrong? Stumped. I'm not sure yet if it's going to come and go as it pleases as it did before, only time will tell. As least the defrost will keep my window clear and my passengers warm until I can work my way though this.

paulo57509

You have two problems you need to diagnose.

1. Why the mode controls only give you defrost. The mode control is vacuum operated. It has nothing to do with the blower motor. The blower motor only blows air.

2. One blower motor speed usually means the blower resistor is bad.

racosun

Noticing a nice sunny day outside with bare roads, I decided to take the car out for a spin, and the heater, defrost, and everything else was working just fine. I have no idea why the thing was doing what it did last night, but it works great today, and with no on/off as it pleases anymore. I have all three speed settings at my command on the heater/blower.

Thanks to everyone who gave advice on this matter. I guess I could have solved it myself yesterday had I just installed the new blower motor when I was going to, instead of worrying about screwing something up worse. Sad to say, but installing the blower motor was the largest project I've ever undertaken on a car, but it was fun and easy. I think I could get into this whole car-fixing thing (if only I had more money, lol).

Mark A Shields

My fan isn't working either.

Tested the wiring and getting 12.21 on the lowest fan speed, 12.29 on the highest.
I assume this means the motor itself is bad?

when ordering the motor, do I need to get the wheel too?

JamesC

iTrader: (5)

Transfer the old cage to the new motor.

JamesC

Mark A Shields

that's what I thought, didn't seem like it was a part that would go bad

Mark A Shields

well, replaced the motor and nothing

NINÅ

ASE doc

It can be deceptive at times testing circuits with a voltmeter. A circuit may show good voltage through the high input impedance of the meter even though it will not support its intended load. Always test voltage on a loaded circuit or use a logic probe such as the "Power Probe". This will point out high circuit resistance that can pull down voltage under load.