Hey guys I’m new to the Blazer world and want to clean my truck up starting with some electrical bits.

I have the A/C temperature control unit w/ rear defrost. The module I have pictured below controls the rear defrost. I notice when I turn my lights on at night this part of my AC unit wouldn’t light up. I haven’t been able to test if defrost is actually working however as weather hasn’t allowed me.

I took it apart and ran a multimeter to it and got back 0V and 0 ohm ratings. Doesn’t appear to be any burning or broken solder points on the unit. Could it be a burnt bulb I should replace? Burnt fuse? Or do I need to replace this unit?

Thanks for the help.

 

The first thing to check is the voltage and ground to the unit by the vehicle wiring harness for the illumination function of the HVAC controller (gray and black).

George

 

It is possible the the bulb has gone out. They are replaceable if you are good at soldering and resourceful in your searches for them. I did this with my radio and steering wheel radio controls.