Rear Heater Core

[tast101]

Well, I guess My Rear Heater is dying, All the rear vents just blow cold air. Anyone know of a way to check to make sure the heater core is working correctly or anything else I should check? And possibly how much a new one would cost? I have a Haynes Repair Manual doesn't look to hard to remove it. Or maybe the lines?

Might just see what teh deal charges to fix it, to get an idea too.

 

[Rivieraracing]

Have you checked your coolant level, it may be low.

 

[tast101]

Have you checked your coolant level, it may be low.

Thanx, I'll check it tomorrow. It's a lil windy and raining on and off in Cali.

 

[boostaholic]

Should be able to find a used hvac for the rear on the cheap, looks like a pain in the ass to replace but it could be worse. Coolant might be low too.

 

[crafty817]

It could be your rear temperature blend actuator... it is a motor that flips a door to blow hot instead of cold... remove the plastic cover over the rear heating/ air conditioning unit.... you will see two of these air blend door actuators. The front one controls whether the air goes to the ceiling or the floor... the rear one is the one that you want.it controls whether you get heat or cold... it is my understanding that you can swap out these motors because they are identical.... so you can use the forward one to see if the rear one is actually bad... I am having the exact same problem. But after swapping the motors I have decided that it is not the motors (actuators) but something else, which is what I am trying to find out now!!!! Anyway. I just turned the rear motor to "hot" and didn't plug the motor back in.... at least the rear seats will have heat until I can figure out what keeps switching the actuator to cold! Tell me what you find out!!!

 

[crafty817]

oh yeah... when you remove the rear plastic cover you will be able to feel the warm areas of the heater... immediately showing that the heater core is sending back warm water (once the Tahoe is warm of course)

 

[TravisH]

I had an issue once where I wasn't get any warm air either. Truck was at operating temps. It almost seemed like it took awhile for the coolant to circulate to the rear hvac. After a couple minutes the air finally decided to warm up.

Maybe turn it on and give it a little time?