Some while ago I had a problem with lack of function of blowers for the climate control. I was getting no power from the microswitches to the relay. I pulled Climate Control Switch out and cleaned the microswitch contacts and it started up again. Recently, it konked out, came back and then konked out again. Figuring I had old bad microswitches, I replaced all the microswitches but this time it hasn’t solved the problem.
Here’s what I’ve done so far and some observations on testing.
I’ve isolated the problem to something after the microswitches and before the relay. Relay is not getting power, and I know this from testing.
Power is coming into the climate control switch. Climate control switch is working properly. I have tested and retested and replaced all the microswitches with brand new. All old and the new microswitches tested fine on bench testing.
Now, when I plug the green wire into the correct miscroswitch terminal I get power. With no other wires plugged in I get full power on each of the other terminals of that microswitch when the switch is set for its respective position. As soon as I plug any wire in to a terminal with the correct power setting (in other words discount that I have the selector and wire combination misconfigured), the power disappears.
So, in normal operation the green wire brings power and the pink goes to ground with the switch in the “Off” position. With the climate control switch turned “On” (that is to say to Lo, High, Defrost or Auto) the Brown wire takes power from that microswitch to the next microswitch.
In my case whenever I plug in any wire to any terminal (the pink one or the brown one) on that microswitch, Power goes from 12V to .0007 volts. I thought it might be a bad resistor, but it does it for all wires even ones that aren’t on the resistor’d line. As soon as you touch ANY wire to the terminal the power that was there a millisecond ago is gone.
I’m thinking a bad ground but don’t know enough electrics to say for sure whether that would account for the problem. Any ideas?
Again, the problem is definitely between the switch and the relays and having something to do with those wires in the harness that service the microswitches.