Good morning and yes you are correct its B0 I guess when I type I just automatically went with what my mind knows for engines, anyways after removing the B pillar I found the wire harness for the overhead cabin temp sensor but no sensor, I also found the hole where the PO or headliner shop covered over. My next step is to buy a sensor a connect it, I will tackle the front (Top Front of HVAC Assembly) in the spring when it gets warmer out so I don't crack any plastic on the dash, unless someone knows a different way to get to it .

Thanks

 

What was the the PO or shop thinking...

Anyway Good job, looks like you're on to it.

 

The one in the headliner you will need to also get the little grille for it as it sounds like they removed it and just covered over the hole where it was. It is actually a small fan with a thermistor and over the years the little fan in that one can start rattling and making noise. GM calls it an aspirator....

You will need the actual fan/sensor - ASPIRATOR, I/S AIR TEMP SENSOR (ACDelco #15-51256) GM Part# 20931026 - NEW ACDelco PN# 22834330 $24 on Amazon (I bought this same one to replace mine which was making noise)
And the little grille for it.... - GRILLE, I/S AIR TEMP SEN ASPIRATOR (GRAY) GM Part# 15075507 and here is the little grille for it for $11 on Amazon...

 

Thanks to all for the help I'm headed overseas for a deployment in a few weeks just making sure the system is working some what so when my wife uses it to travel up to NJ for xmas she will be ok. Any easy way to replace that front actuator ?

 

I'm not sure on the H2. I know on my GMC truck that one can be done through the glovebox lid but it is a big pain and you are working blind. I'd imagine that one on our H2 is probably about the same. Might could remove the grab handle, airbag, and dash panel there (not the entire upper dash) and go through that opening too. I'm almost certain I've read others on here replacing that one without removing the entire dash. That upper one is just the recirculation/fresh air door though so that should not have a huge impact on temperatures as much as it can affect how quick and effective defrosting/defogging will be.

 

How will it affect the AC in Summer? I'm not too worried about defrosting its more cabin temp for winter and summer

 

It just is whether it recirculates inside air (max AC mode) or brings in fresh air. It does affect the temps but not massively.

 

Thanks, I appreciate the help

 

MixManSC great references and advice