is there a 'master' blend door that would explain this?

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

S33k3r

Full Access Member
Joined
Aug 14, 2017
Posts
2,254
Reaction score
2,977
Location
Dallas, Texas
final thought, just thinking outside the box...do the passenger/driver blend paths ever...cross paths? In other words if the driver blend door was fine, but the passenger one was broken and bleeding off, would any of that hot passenger mix be able to get into the driver side path?

I didn't dig a lot into this as I ended up paying a mechanic to fix it. But the symptoms I suffered were running AC because it gets freaking HOT in Texas, and having the driver's side -- and ONLY the driver's side -- blow heat; everyone else got AC.

But, from the information I have read across multiple GMT800 groups, there are three doors/actuators/whjat-have-you in the front on the GMT800 trucks; one at the driver's footwell, one at the passengers foot well, and one completely behind the dash. The one behind the dash is rated at 9 hours of labor to disassemble the dash, replace the problem part, and reassemble the dash.

As an aside, and this is a wild-ass guess, there are separate units conditioning the air between the front and the rear systems. There is a part, for example, in the right rear wheel well (inside the cab) that has something to do with air going to the back part of these trucks. So I am thinking that bmishoe's problem is something under the hood as opposed to a door issue. But, at this point, taking it to a mechanic and getting it professionally checked would seem the wisest course of action. The trick there being making sure you had a mechanic you can trust.

I don't know where he is located, but if he is in the Dallas/Ft. Worth Area of Texas, I can direct him to an honest mechanic.
 

Rocket Man

Mark
Supporting Member
Joined
Dec 25, 2014
Posts
25,961
Reaction score
50,621
Location
Oregon
I didn't dig a lot into this as I ended up paying a mechanic to fix it. But the symptoms I suffered were running AC because it gets freaking HOT in Texas, and having the driver's side -- and ONLY the driver's side -- blow heat; everyone else got AC.

But, from the information I have read across multiple GMT800 groups, there are three doors/actuators/whjat-have-you in the front on the GMT800 trucks; one at the driver's footwell, one at the passengers foot well, and one completely behind the dash. The one behind the dash is rated at 9 hours of labor to disassemble the dash, replace the problem part, and reassemble the dash.

As an aside, and this is a wild-ass guess, there are separate units conditioning the air between the front and the rear systems. There is a part, for example, in the right rear wheel well (inside the cab) that has something to do with air going to the back part of these trucks. So I am thinking that bmishoe's problem is something under the hood as opposed to a door issue. But, at this point, taking it to a mechanic and getting it professionally checked would seem the wisest course of action. The trick there being making sure you had a mechanic you can trust.

I don't know where he is located, but if he is in the Dallas/Ft. Worth Area of Texas, I can direct him to an honest mechanic.
Yes, the front and rear have their own separate systems. The rear is located behind the passenger side rear compartment. There’s a separate heater and ac unit there, with its own blend door and mode door with corresponding actuators. Up front there’s 4 actuators- blend doors for passenger and driver temp control, mode door to tell the air which vent to blow out of, and recirc door to tell the system to either draw outside air in or to recirculate the inside air. The recirc is the hard one on the NBS. I replaced mine in a couple hours by only removing the dash cover and then removing enough screws from the supporting structure that I could pry it up enough to get to it.
So in total that’s 6 actuators.
 

Sparksalot

Supporting Member
Joined
Sep 20, 2020
Posts
5,062
Reaction score
13,735
Location
Bastrop County, Texas
Yes, the front and rear have their own separate systems. The rear is located behind the passenger side rear compartment. There’s a separate heater and ac unit there, with its own blend door and mode door with corresponding actuators. Up front there’s 4 actuators- blend doors for passenger and driver temp control, mode door to tell the air which vent to blow out of, and recirc door to tell the system to either draw outside air in or to recirculate the inside air. The recirc is the hard one on the NBS. I replaced mine in a couple hours by only removing the dash cover and then removing enough screws from the supporting structure that I could pry it up enough to get to it.
So in total that’s 6 actuators.
Are the actuators themselves the same part number, or is each one different?
 

Forum statistics

Threads
128,802
Posts
1,805,644
Members
91,785
Latest member
Eliteweapons
Top