Heater only blows hot from all vents

[Gary_44]

Hello all. I just joined the forum, since I just bought a retired 2010 Tahoe SSV. It has a few small issues, likely from the disconnecting of all the cop stuff.
Top of the list is the climate control only blows hot. Fan speed works fine, but no matter where I set the temp dials, it blows hot. This is on both driver and passenger sides, as well as the rear vents. I did some searching, but only find a bunch of topics about the drivers side acting up, not all of them. Any ideas where to start diagnosing?

 

[Big Mama]

I guess the easiest thing to check is to make sure your AC compressor is working. Check the fuses to make sure they're all ok. I can't remember exactly but I think these are in the engine bay fuse panel. Check the fuses first. If they look ok check the compressor. Start the truck without it on then see what happens when you turn it on. My uneducated guess is that the fuses are ok, as is the compressor, but you have a leak in there somewhere. There other thing to check is on the post you mentioned or simply search for "Dual climate control only blowing hot" If that's the problem it's a tough one to fix but you can do it. Just start eliminating possible issues by starting with the easiest things first.

 

[Gary_44]

thanks for the reply, but I dont think it is AC related. The weather here is 20 degrees, it should blow colder than full hot without using the AC.

 

[Big Mama]

Agreed but with more than one climate control area in your Tahoe it's a good thing to eliminate. If you're looking for the next thing to check it's the blender inside your dash that's probably stuck in the heat position. Blender probably isn't the right word but there's a gate/door in your dash that opens one way for heat and the other way for cool. Did you have any luck looking up climate control on the forum? As I stated earlier it's usually not an easy job due to all of the things you have to remove to get to it but you'll save a ton on labor if you can. One thing I've done in the past is go to my local mechanic and pay him the $60 hourly rate to verify my diagnosis then I find the info here on how to fix it. For the times I'm not sure what's wrong it'd money well spent.

 

[PatDTN]

Just spent a half hour researching a similar issue. Look for information on recalibrating actuators. Basically you need to disconnect the battery for a while. Folks mention 1/2 hour for that. Reconnect the battery and turn the key all the way on but don't start. Don't touch any controls and wait 10 minutes or so then start and drive up to highway speed for a few minutes. Park and shut down the truck and get out and close the door. When you get back in it should be working.

Some of this procedure will recalibrate running gear as well as the HVAC. I just read all this and haven't tried it yet.

 

[2011SSVHOE]

Another thing I would look at , make sure the harness connectors are hooked up on the back of the climate control just my 2cents

 

[Big Mama]

Agreed the fuses and compressor are usually ok. Wouldn't surprise me if the PPV edition eliminated the passenger and rear controls. It'd be hard to reach wearing hand cuffs. The blender is a possibility but it's rare that they fail. It's more likely the electronics controlling it are disconnected or altered being a police version. Check fuses then compressor then controls then other fuses involved with climate control then blender. Granted the driver control should blow cold with 20 degree weather

 

[PatDTN]

Just like to point out that the recalibrate procedure is very simple if a little time consuming.