Hello,

Over the summer our 1998 Blazer sat for three months on return home none of the controls on the module are working. I checked all the (3) HVAC circuit breakers and they check fine. Before I start throwing parts at the blazer is there a separate circuit breaker for the module? Or is it obvious since all three of the controls are not working I should just replace the A/C control module?

Thank you,
John

 

Here is a photo of the controller I have in the 98 Blazer. I was able to determine the blower is working fine based on hardwiring at the blower motor control module. When I change the temp control no temp change is felt while driving. A small amount of air comes through the vent. Location of the air does not change as well. I would think that if the computer climate control was still functional the temp would change as well and the location of the airflow. Would the blower control module effect this too or just the operation of the blower motor?

Thanks,
JM

 

Your fuses are:

UHFB: HVAC fuse, Ign E fuse, A/C fuse

IPFB: HVAC1 fuse, RDO batt fuse


George

 

Thank you George, Went through each fuse individually yesterday but will replace the ones mentioned later today and get back to you. Good information.

JM

 

Let me know if that does not do it.


George

 

Went through all circuit breakers mentioned and replaced them with others to be safe. Also exchanged the A/C relay with another too. No luck. Nothing on the computer climate control is functioning. I removed the unit. This model number (09356175) is not as available as the manual control unit. I did find one on eBay used for 79.00. I need to look over the return policy again. Will look for new this afternoon. Also will look to see if this one can be bench tested. The chance of finding someone on the Big Island of Hawaii is very remote.

 

Does anything turn on: ac compressor, blower motor, vent positions?

George

 

No nothing.

I did hard wire the blower motor down stream from the blower control module and the blower works fine.

 

We can run some tests to confirm no output but if all functions are dead then its most likely the hvac module.


George

 

Sounds good. I have a volt meter will that be adequate. Is the HVAC module the unit I have a picture of on this thread?