heater not working
at first i lost high and low settings on my heater switch, then the whole switch
quit working. the climate control module has been replaced. when the switch
is turned on you can hear a clicking noise from under the dash on the
pasenger side. the coolant lines running to/from the heater both heat up when
the truck is running.
Sound like a AC actuator module that controls the blend door. So the blower motor is working?
The clicking noise is a bad blend door motor. If you lost your fan speeds, you also need a blower motor resistor. Here is a video on what you will basically have to do if you fix it yourself....................... https://www.youtube.com/watch?v=ABRG1Vh8igE
Could the fan speed problems be due to miswiring to the resistor
Mlkamp, generally no. Most resistors just plug into an existing socket. If the vehicle had been miswired, the problem would have started from the get go. When the resistor begins to fail, you will lose speed 1, then over time speed 2 and so on until it fails completely.
I changed the wiring harness, possible I crossed wires
If the fan was working fine before the harness install, then yes, you may have done just that.
The plug in on the wiring harness to the blower has letters on it ( a-g ) do you know how they correlate to the wiring coming from the controls
Mlkamp, not without a wiring schematic. You may want to start a new thread with your model and year. Hopefully there's a GMC guru who would know.
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