Still having problems with 94 Blazer's blower motor

search for 94 Blazer blower motor to find my previous correspondence about this. I can’t seem to reopen the original page. Have replaced the relay and the resister block and still have the same thing happening. But I think it is actuall working on low, whereas I initially thought not.

So, seem to have low when turned on any speed, and can get high by setting on high, engine running, and either tapping the relay or unpluging the purple power source wire.

I want to know whether this could be the control switch in the control assembly and whether that switch can be replaced without having to replace the entire assembly.

I’m afraid that thing is going to cost a bunch more than the relay and resistor block, so am hoping to get a definite answer before I buy one of those!


a/c blower motor on 94 S-10 Blazer acting up
Seems to only work on high and have to have car running, control switch set on high, and go under hood and either tap the relay or unplug and replug power lead (purple wire to motor. Motor immediately comes on full blast. If car is turned off, or control switch is turned to lower setting, blower stops. I can still feel cold air coming from vents, but am not sure whether the low setting is working or if it’s just coming out without the blower.

I replaced the relay, since tapping the old one made the blower come on in the manner described above. But it’s still behaving the exact same way with the same response to tapping or interrupting the power source briefly.

Could it be a resistor? and if so, how do I find it? Is it in the form of a wire? I have the shop manual, but could not find my car’s symptoms in the trouble tree and could not tell from the diagram where that resistor might be.

Posted by: E. Menger

You need a 12 volt test light and then you can check for power at the blower motor connection.

If the light comes on bright when the switch is turned to high speed but the motor doesn’t run then the motor is defective and needs to be replaced.

You can also check for power from the resistor block by checking the brightness of the light when the switch is set on the lower speed settings. The light will be very dim on the slowest setting and get brighter with each higher speed setting.


There is power to the motor and the motor works in low (no matter what I have the control switch in the dash set to) and on high (when I put the control on high, engine running and go under the hood and either tap the relay or unplug and replug the purple power wire to the motor. So the motor’s working, the relay is working and the resistor block is working. (Besides, I replaced the relay and resistor block already.)

I THINK that must leave the dash switch or the wiring harness.

My question now (before I try taking the control assembly out) is whether ya’ll think it’s the dash switch perhaps worn out and also, is the blower speed control switch separate from the rest of the assembly, or am I going to have to buy the whole thing.

Finally, what is it about this circuit that makes it possible to get the blower to come on High by that tapping or interrupting the power source? And I have to do it every time I stop and restart the car, or turn the switch lower than high.

One more question: Is there a coating on the resistor coils that emits a burnt smell when they are in the circuit. It’s a new resistor block and smells when I have the switch set on low, med. low, med high, but of course, not when it’s set on high since the resistors are all out of the circuit then. I’m guessing that it’ll eventually burn off, if that’s what it is.

I sure hope some of ya’ll will get back to me on this, and I thank you, because I’m a 50-something year old retired housewife who, long, long ago, in a galaxy far, far away, used to work on cars…no joke. Thanks!

You can try disconnecting the switch and using a multimeter to check it.
When the motor doesn’t want to start, will it start if the fan blade is carefully poked with a stick to get it moving?
Use a voltmeter to check for voltage at the motor and a clamp on ammeter to check if the motor is actually drawing current. See if it matches spec.