HEATER NOT WORKING PROPERLY

by Christopher
(USA)

2004 Coupe with Auto Trans and Dual climate control HVAC system. I just purchased the Vette in September of last year. Took awhile to notice the problem as I live in Minnesota and couldn't drive it much in winter. So I can't say if the problem was there before or after I bought the car. System puts out hot or cold air and from the correct vents when being used. Fan works fine. I do not use the automatic setting, prefering manual control instead. BUT there is a temperature control problem at a specific temperature setting, whether in auto or manual mode. The Chevy mechanic is stumped.

OK here goes...if you set the temperature control at 80 degrees (in manual mode) after the heater warms up and starts putting out very hot air, soon or later the hot air disappears and cool air (not cold as if a/c came on) starts coming from the vents. If you increase the temperature to 85 degrees or higher, you get the hot air back. Return to 80 degrees, you get the cool air back. This problem can occur within 5 minutes or 30 minutes or longer, as the time period varies). I've had instances where I've shut off the car and come back and the problem is still there and instances where the problem is gone.

The mechanic is researching the problem, in between jobs at work, trying to pin down the problem before having to take apart the dash to troubleshoot. He did have me cover up a HVAC sensor on top of the dash in the grill's passenger side but that did'nt change anything.

Any suggestions are appreciated. Thanks

Chris Trautman @ Corvette Assembly Plant 2019

About Us: Corvette Web Central | Owner Bio: Chris Trautman

Established in 2008 by Chris Trautman, Corvette Web Central quickly grew into one of the top leading Corvette enthusiast websites globally. 

"This website is a passion of mine, just as much as being a Corvette owner," says Chris.  He was frustrated trying to find information on the internet about Corvettes which was was not biased or influenced somehow. 

He has owned three Corvettes over the last twenty years and does not plan to stop owning one anytime soon.

Note: Some links on this page are part of our affiliate program and provide a small portion of proceeds to fund the administrative costs and to fund more product reviews.  We are not paid to perform the reviews or are we given any products for free.