GFDI! Broken rear heater... maybe

[tybardy]

My front heater works just fine... but the rear heat blows cold. Is there some sort of actuator or something that is not switching over? Obviously the heater coils are working just fine and the blowers are actually blowing... just not hot

 

[yooformula]

from what I have read and plan on doing, it sounds like the actuator in the rear cargo area, pass side. Sounds like the blending door or w/e is stuck in the cold position. I have the same issue with mine, was intermittent now just blows cold constantly yet the heater core has hot lines on both sides.


link...http://www.fullsizechevy.com/forums...e-rear-air-has-no-heat-just-blowing-cold.html

 

[road1will]

Yea, the blending door is most likely stuck. I think its pretty common on these trucks. My dads old '04 suburban had it happen twice.

 

[nicegy31]

I have the same problem. I found that the part that the actuatior control was broken I had to changed the upper console now I have to do some more troubleshooting. Both actuators are not working. I swapped them and neither one is moving. Does anyone have the write up on what wire has voltage on them I seen it in the forum before but can not find it now?

 

[vatahoelt]

I have the same problem. I found that the part that the actuatior control was broken I had to changed the upper console now I have to do some more troubleshooting. Both actuators are not working. I swapped them and neither one is moving. Does anyone have the write up on what wire has voltage on them I seen it in the forum before but can not find it now?

after installing the new actuators, did you do the re-learn process?

did you check the fuse under the hood to make sure it was still good?

even with them not working properly, it's uncommon for them to not move at all.

 

[kses123]

Did you update to the new actuator controller module? It is a little computer that has updated software in it to prevent failures.

 

[03Dnasty]

My truck has the same issue right now. Kses123 how do you do this relearn process?

 

[kses123]

I don't remember there being a re-learn process for the rear. My actuator was stuck on cold. I found the GM bulletin online about how to fix it. Replace the actuator as well as the little control box. I got them both on Amazon. I had the battery unhooked and installed everything. When I hooked it up, I didn't touch anything. It ran a little self-test then everything was working normally again.

 

[03Dnasty]

Yeah, I took my rear panel off today and found that the one actuator is stuck on cold. I can manually turn it to heat and it'll work. The cheapest I found on Amazon.com was $70 which is better than the local parts store wanting $116!

 

[stormin]

mine now works....

I was reading somewhere... that if you disconnect the battery... and let it sit for a few mins.. then reconnect battery... the system or the control for the actuator... can .. "relearn"...

so that's what I did ...and I now have heat once again in the back of the tahoe!

good luck all

take care
NB