Hello,

New member here. I just picked up a 2005 Suburban 2500 LT 8.1 4x4. Lots to love about the truck, and have already found some great answers here by searching around, but one particular problem has me stumped.

I noticed almost right away that the automatic climate control would only blow air from the defroster vents, no matter what position was selected. I ordered and installed an AC Delco replacement mode door actuator (15-73952). It now functions perfectly as far as blowing air out of whatever vents are selected.

But... On a cold start, and only if the weather is cold, it will make the same kind of grinding noises that they make during calibration for 2-3 seconds. It's silent in normal operation, and is fine on subsequent starts throughout the day, or if it's warm outside.

I've tried disconnecting the battery and recalibrating the doors several times to no avail.

Am I looking at a bad part, or did I install it incorrectly? It's hard for me to jump right to thinking I installed it incorrectly, because it works exactly as expected despite the initial noise... Any ideas?

Thanks in advance!

Tom

 

On further investigation, it happens the first time it goes to the defrost position. Did I screw up the install? Anybody?

 

theres not much to go wrong installation wise, I would think if it wasn't mounted right it would have issues all the time. The door may be binding a little when cold due to the temperature or maybe needing lubed.

 

Thanks. I'll probably pull it back apart over the weekend and double check my installation and lube whatever I can reach. I really don't want to pull the dash out of this thing...

In the meantime, I'm quite pleased with the way this truck totally fails to acknowledge snow on the roads. Hit the automatic 4wd and it just keeps going and going and going!

Tom