[Carnyewest]

So I've spent weeks trying to fix my issue, it began with the front vents not blowing any air. I could feel the air getting cold or hot, everything was fine just not actually blowing. I replaced the blend door, worked for a day then stopped. Tried another blend door, nothing, replaced resistor, nothing, replaced blower motor, nothing. Randomly a day later it starts working, but then the 2nd row ceiling vents stop blowing. I checked the rear blower motor, fuses, etc. Everything looks fine just like the front. Next day everything working again?! Everyday I get in my car there's a 50/50 chance air blows in any vent. Sometimes I start my car, haven't ran the A/C in weeks, after a few minutes the front vents will kick in even tho the rear ones work on start. Front glove box area also makes an incredibly loud hissing sound when fan is turned to max. Dont remember that being so loud.

One more thing that may or may not be related but my drivers seat airbag light comes on occasionally, driver heated seat cuts off after 2 or 3 min, passenger seat fine.

I've looked thru the forum, youtube, etc. All I see is blend doors, resistors, blower motors then threads about issues with air not getting cold. Everything in my car works as it should, I'm just not getting any air thru any of my vents consistently. One may start working, then the other won't or sometimes they both work just fine. Its getting cold out, about to give in and pay the dealer thousands of $$$ i really don't have w/ Christmas coming. just can not find the issue. I'm assuming I have a short or electrical issue. Vehicle has 126k miles. No major repairs, never damaged, etc.
Has anyone had these issues? If so, what resolved it for you?

Any help is greatly appreciated. Thank you in advance!

 

[divotdug]

I would be testing the climate control module and the associated wiring and connections.

Would also be checking of evidence of water intrusion in the blower motor housing.

I'm sure the problem is solvable but it could get expensive because for some issues the entire dash assembly needs to be removed.

 

[speleos]

Also make sure the front and rear-seat climate controllers are in synch with each other.

 

[Carnyewest]

Thanks for the info so far. The rear and front climate controls are in sync. So far still having same issues. Front vents work if I have it on highest setting. Anything lower 50/50 chance it either works, fan sounds like its working but just a little air blowing or it doesn't do anything. Rear overhead vents still work on some starts and not working on others. Forgot to mention all of this started like a couple weeks after the dealership replaced my headlights under the 10 year/120k mile warranty. Probably unrelated but forgot to mention.

Just recently noticed when I start my car, I'm also getting a delay with a weird sound like it is not going to turn over, then it does. Not sure if alternator is going out or if i have a short and its causing it. Its all slowly falling apart. Checked for water in the front, removed glove box/panels passenger side and in rear after basically removing the whole trunk. No signs of water. Still have roughly 2 years of payments on this thing, but I definitely don't want to drive it even 1 more day with things going this way. I don't really have another option until its paid for though. Gonna try my local mechanic this week 1st then go from there. He's got no clue either but hasn't had a chance to look. Fingers crossed I get some answers soon.

 

[speleos]

Have the mechanic check to see if the outside temperature sensor is working. The connector may have been bumped or wiring messed up when the headlights were done.

 

[Carnyewest]

I think I have discovered the "cause" of the issues. My wife drives my car from time to time and uses a 12V power inverter. She left it plugged in my vehicle and it wouldn't start. I unplugged it and my vehicle started right up. My air temp, fan speed, etc was randomly setup on different settings from when I last drove it. I'm sure all of this is related somehow. As to the damage it has caused with my HVAC system will be the key, I assume. Any advice on what I might be able to check or how to reset the system after I drive it awhile to let the alternator get some juice flowing back into the battery? I could be wrong, but feels like this is my main issue, 2nd issue being the heating pad in drivers seat needs to be replaced and/or a short. I don't think the heated seat not staying on/ssrvice air bag light is related to the other issues. You guys rock! Love the helpful advice knowledge and brainstorming going on. I'm apparently brain dead how I haven't connected the dots with the power inverter.

 

[speleos]

The HVAC may reset itself after a few drive cycles. The forum search can lead you to reset instructions if you want to find out how to do it anyway.

 

[Carnyewest]

Thanks, the power inverter has been removed and my car is still having trouble starting. Luckily it eventually starts. Sounds like its just getting worse and worse, and more expensive. Eithee my battery is going bad causing everything to reset/not have enough power to run the HVAC, or I've got a serious short causing everything to go crazy.

 

[Carnyewest]

Thanks, the power inverter has been removed and my car is still having trouble starting. Luckily it eventually starts. Sounds like its just getting worse and worse, and more expensive. Eithee my battery is going bad causing everything to reset/not have enough power to run the HVAC, or I've got a serious short causing everything to go crazy.

I'm going to replace the purge valve....for the 4th time. See if that helps anything, it's going bad again. Hopefully by the end of this week or next, I'll have some answers from my mechanic. Thanks as always!

 

[MI-Acadia]

Eithee my battery is going bad causing....

Easy enough to get the battery load tested to see if that may be the problem. I can confirm that a marginal battery can cause a plethora of problems with all the electronics in modern vehicles.