brossow

2006 2LT with heated seats and all the goodies. Never had any significant issues aside from the power mirrors that have never worked since the day I bought it. The other day out of nowhere it just started blowing hot air and I noticed that the HVAC controls weren't lit up and didn't respond when I turned the knobs (hot/cold or vent controls). Fan control worked (and continues to work) just fine. Got home and didn't think much about it for a couple days, and suddenly they started working again. Now today they're once again gone. After several key cycles they came back, but then were gone again after I turned the key off and back on.

Any thoughts? I can't see any fuses that look blown, and the diagram on the fuse box under the hood doesn't have anything labeled that looks relevant. Am I missing another set of fuses, or is there something else I should be looking at? Blowing only hot in the winter is one thing, but it's finally getting warmer outside and I need to get this sorted out.

Thanks in advance!

Brent

donbrew

There is the "other" fuse box. Passenger side of the console.

There is a link to your Owners Manual in my sig.

brossow

Thanks, donbrew. Either I didn't know that was there or had long since forgotten. Either way, I pulled all of the fuses and they all looked okay. Through several key cycles during the process the power came back to the controls a couple times, but it was gone again the next key cycle. No rhyme or reason to it that I can see. Anything else to check? Hate to pay shop rates to take it to the dealer, but we're in the middle of trying to sell our house and buy another, and I just don't have the time to start tracing wires.

donbrew

I was working on the wiring diagram and my computer crashed, sorry. I don't ave the program on this one.

I think it may have something to do with the back up light fuse. I'll try again tomorrow.

donbrew

Working from memory; the heated seat runs off the back up light circuit and tha HVAC controls run off the parking light circuit.

Also a 2 amp fuse somewhere and the ground for both is left side of the dashboard.

I didn't have time to really look closely though, so not gospel.

brossow

Thanks, donbrew. A bad ground would explain the intermittent behavior (it was fine again this morning). Those give me more things to check at least. Will update if/when I resolve the issue. In the meantime, any other suggestions are more than welcome. Much appreciated!

ChevroletCustomerService

Hey Brent,

I know donbrew is an excellent resource, but if you'd like assistance in reaching out to your local Chevrolet dealership, I'd be more than happy to do that on your behalf. Especially since it looks like you're preoccupied with your move, I know how hectic that can be!
PM me with your VIN, contact info, and preferred dealership if you'd like me to proceed with that.

Additionally, let us know if you have other questions as well. We're here to help!

Geoff G.
Chevrolet Customer Care

brossow

I pulled everything I could bear to pull out of the dash this afternoon and can't find anything wrong. Every fuse is fine, no wires I could see that look bad. Electrical isn't my thing, so I think I'm going to have to be at the mercy of a mechanic. It keeps coming and going, and I can't have hot air blowing at me as we head toward summer. Geoff, I'll send you a PM.

I'm open to any other suggestions. Not sure where to look for the ground for these, but that sure seems like a possibility.

firemangeorge

After rereading your posts, seems that you lose AC cooling ? Then it returns after a few key cycles. Am I reading this part of the problem correctly ?
And you still have ability to control the fan. Correct ?

If this is the case, remember that certain CEL's will not let the AC compressor engage.
It could be you have a CEL code. Showing or not(maybe one is stored)
You should have the codes pulled and checked.

brossow

No, it's a loss of power to all the controls except the fan switch. Can't turn the heated seats on. Can't switch from outside air to recirculating. Temp control knob has no effect, nor does the one that changes where the air is blowing (dash vents, feet, defroster, etc.) I don't think they're even getting power as they are not lit up at all (except when they occasionally decide to work).