Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum banner

2007 LT Problems with AC relay and Sunroof

3129 Views 3 Replies 2 Participants Last post by  atineo1982
First I'd like to say hello. I'm from NY and I've recently acquired a 2007 Trailblazer LT with 32,XXX miles. I love everything about this vehicle except the gas mileage, but that's for another thread.

I'm on here trying to figure out what's wrong with my truck. One day I turn the heat/ac on and I hear this ridiculously loud knocking. I started messing around with the vent control and the noise seems to turn off when it's in the foot/chest setting. Any other setting including the foot or chest (solo) setting the sound starts. I'm guessing its a relay somewhere but I don't know where to start looking. Any help would be much appreciated.

Next issue...

Yesterday I tried opening my sunroof to let a little air in and I heard a "snapping" noise. Like as if something broke. I tries to open/retract the sunroof and only after a coupe of tries did it open. It was working fine until today. Now it won't open and it looks like when I try to open it, the driver side part of the sunroof appears to be stuck on something. I can't see what exactly is going on there because of the tight space but I was hoping someone here went through a similar issue and found a simple fix for this.

Once again I'm a newbie to these trucks and would love to keep it until it deteriorates because I bought it with hopes that I'd pass it down to my 1st born (16 years from now) arriving in August.

Has anyone here experienced any one of these issues and if so, how/what were the fixes. Any info would be greatly appreciated.
1 - 4 of 4 Posts
The knocking sound sounds like it could be the mode door actuator on its way out. Mine did it for about a week before it finally failed and then I could only get air out the floor vents or the defroster.

The other may need a trip to the dealer as it sounds like something broke in the sunroof mechanism.

I saw that write up... It seems a little bit out of my skill level. Quite intimidating actually. I might have to shell out a few bucks to get the sunroof fixed.

Do you have a website or/and a part number for the mode door actuator?
1 - 4 of 4 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.