Hi,
After searching thru this forum trying to find a solution to my air conditioner blower motor which I was not able to find, I found the problem myself.
Now I hope this helps someone.
Problem was that blower motor ran only on high speed.
All leads in this forum and others I visited pointed to the Blower Motor Resistor Block (BMRB) which I replaced and did not fix the problem.
After studying the circuit diagram for the blower motor it showed that the current came first thru the blower motor switch then to the BMRB on the lower 3 speeds. On the high speed, it totally bypassed the the BMRB by way of a Blower Motor Relay (BMR)
I noticed that the BMRB was getting current but was not going to the Blower Motor which then pointed me to the BMR which I replaced and fixed the problem.
Hope this helps.

 

Hey, thanks.
I have the same situation, and you just saved me the time of having to track down the circuit.

 

I have the same problem only mine doesn't work on high and only sometimes on medium. I tried replacing the resistor and it didn't help. Where is the BMR, could that be my problem also?

 

jillbean,
My BMR was near the Resistor block about 12" away, you can try swapping with a new and see if that is your problem. If that does not work, check your switch by unplugging the connector that goes to your resistor block and testing each terminal with a voltmeter or multimeter preferably a test light and as you switch each speed on your switch you should detect current on each of terminals, of course doing so with the ignition on to make the fan start.
Hope this helps.

 

Thanks for the response. I haven't tried a new relay yet, but, I tested the wires as you suggested. At first only the first one lit up, but, when I got the blower to work on the third setting, which it only does sporadically, then the third wire lights up. Does it sound like the relay or maybe the switch?

 

I tried the relay, no luck. I ordered the switch, hope that works!

 

Sorry I could not get back to you sooner.
I was going to suggest that you inject 12 volts to the motor to see if it runs at full force to verify that you have a good motor, that is if you have not already done this, before ordering a new switch.
Motors do tend to wear out.

 

Thanks again. All speeds worked if I messed with the switch. I took the switch out and the wire harness plug is melted pretty bad. I don't know what to do now.

 

Make a diagram of where the wires go. Disconnect the battery. Cut the wiring harness back to the point where the wires are still good. Crimp on new replacement female spade lugs, AKA "quick disconnects" and then reconnect to the proper locations. You can splice in some new wire to make up for the lost length if neccessary.

 

Thanks to you both. I did add new insulated plugs to the wires at the switch and it works great! There doesn't seem to be any heat on the connections, so, I don't know why it melted in the first place. We'll just have to wait and see, I guess. For now, it's nice and cool!