I have a 1998 Blazer 4.3L V6. The A/C suddenly stopped working and noticed the climate control computer is not responding. The lights don't turn on when the headlamps is on. The switches and ***** don't do anything. I checked the HVAC and A/C fuse and relays and even swapped the Body Control Module (BCM). When i tested the electricity from the wire connection to the climate control computer, there is 12V coming out. But when i connect the climate control computer to a separate 12V battery it works. Even the lights are working. I checked the resistor and it's all fine but i don't know how to check the blower motor controller. The A/C blower is working fine except for the climate control computer. Is there something wrong with the wirings or is something possibly broken or not functioning well? Is there a way to turn on the compressor and the blower without the climate control computer?

 

Is this manual or auto HVAC?

What wire are you adding your own 12V to that turns on the HVAC controller?

If you measured the original power wire voltage with the harness disconnected from the HVAC controller, hook it back up and back probe that power wire with the "load" attached. I bet it drops to zero.


George