Hello, I'm new to this forum and glad I found it. My question I hope simple and someone has had same issues at one time. So, all of a sudden my uplander will blow air out of rear vents top and bottom when selected but, there is no longer heat out of the rear vents when heat is selected. I haven't tried to run the ac to see it that works yet will try later. So , any help is good help. Thanks, Mike

 

@scamr7; Welcome to the forum. There are some people on this forum with mechanical experience. They look in from time to time. You should get some sort of response to your question.
Perhaps a bit more information about your problem might be helpful. ie: mileage on your van, are you getting heat at front heater of your van? Is the temperature gauge on the dash showing that the engine is running up to temperature? If you have a current subscription with On Star, call them and ask for a diagnostic check on your van for any problems that it might detect.
Personally, I have never had any problems with the heater system in my van and I have 149000km [92000mi] accumulated.
Winter just arrived [major snow storm] in a big way today in Alberta, Canada. No doubt you will want to get this problem fixed before too long.

 

What model year do you have and what is your current mileage?

Jeff Morris, Chevrolet Customer Service

 

If you guys are having problems with your rear heat we need to all call this number and put it under your GMC VIN # and complain. I called today and they said there were no other complaints regarding rear heat in the uplanders. Mines an 08 and had to be flushed twice in the past year. Dealer keeps saying air in the lines. Clearly it's not if so many people are having problems.

Number is 18002633777 and follow the promtps.