Having issues with my climate control system. For the longest the fan speed switch kept dropping speeds until now it won't work on any modes. Replaced the resistor and it worked on one speed for a few days then out again. Since then I've replaced the resistor again, the relay, and the resistor plug with zero change. Everything works perfectly when I can actually get it to work, which makes me think I'm not getting power somewhere it needs to be. From looking at the wiring diagram I found I seem to think that my issues is now in the fan speed control module/knob itself but I've also got somebody telling me that the control module isn't the issue, I've got a connection issue or a ground issue somewhere else. Can anybody help me narrow this down on what to look at next?

 

Send hellshotrod a PM , he probably has the HVAC control module for you. Probably for the cost of shipping.

https://www.chevyhhr.net/forums/reti...ime-buy-63306/

 

Will do. Think that could be the issue?

 

Bat+ comes to the fan directly, the speed control switch chooses a route to ground (High speed, no resistor is the default).
If it is a power issue you are looking on the wrong side of the motor. I don't know what schematic you might be looking at.

 

This is what I'm looking at. I know I busted up my BCM3 female fuse trying to check it. I was never able to get it out but it doesn't look blown. I planned on replacing that tomorrow afternoon when I can go by the store. If I'm not looking at a basic electrical issue I'm thinking maybe look at compressor next? I never thought compressor because when I can get everything to blow it blows ice cold. It's just getting it to blow that's the issue.

 

learn how to read electrical schematics. That clearly shows the flow of electrons. Fuses are on the HOT side no fuse on the ground side. It also pretty clearly shows whyu you should be looking at the speed control switch.

You do know there is a fuse puller tool supplied in each fuse box? I don't know what a "female fuse" is. Don't know why you are fiddling with BCM3 fuse.



What do you think the compressor might have to do with the circulation fan? If the fan is off the compressor should not run, the controls run bassackward from your thunking.


Under Hood

BCM

 

Yeah, I know next to nothing about reading schematics. Looking at the first picture you attached I do see that my issue is most likely in the speed control switch now. The way I see it, in insanely simple terms, is that power is fed to the speed select switch, depending on the switch position a different level or area or whatever in the resistor is activated which in turn controls how fast the blower motor runs. Therefore if there's any type of disconnect at the speed select switch, no power is getting to neither the resistor nor the blower motor. Is that halfass right?

 

The route to ground is through one of the resistors. More resistance slower the speed.

Moving wires around while changing things will move burned connections around and make them work until they don't. That's why sometimes it works.

 

Makes sense. I’ll move on getting a control module replacement. I pulled it off once before and saw a hotspot on one of the connections and always thought that was my issue but kept getting talked into different symptoms.

 

So, say hi! to David, hellshotrod!