Hey guys! I'm at my wits end here and could really use some help! The air conditioner in my wife's car stopped working about a week ago. Using information from previous threads, I was able to determine the problem is with the Blower Motor Circuit-DTC 12. I followed the service manual instructions for troubleshooting DTC 12. Everything checked out fine until I got to steps 13 and 14. The blue/yellow wire in the female end of the heater control panel seems to be in the right place, but there is not a blue/red wire, which is supposed to be right next to the blue/yellow wire according to the diagram. At any rate, there isn't any continuity. The instructions say I need to repair an open in the wire between the heater control panel and the power transistor. How do I do that? I'm also not sure that I tested the relay correctly. Can you test a relay using a continuity tester and/or multimeter?

Sorry for the novel. Any help would be much appreciated!

Chad

 

Do this with everything plugged in. Turn the key on and blower switch on high. Measure voltage from each wire at the blower to ground. If both wires have battery voltage, replace power transistor. The problem is usually the power transistor. Finding battery voltage on both wires shows that the fuse, relay, and motor are OK, but the transistor is not completing the ground side of the circuit.

 

I just tested both wires and there is only voltage to the positive wire. Now what? Thanks so much!

 

As there's voltage across the motor (one wire hot, the other grounded), it should run. That it doesn't run, shows that the motor is bad.