Hello all, I'm new to this forum, so I hope this isn't already an open topic. I have a 2000 Chevy Suburban K2500 LT with the 6.0L Vortec engine. My heat stopped working in the FRONT zone ONLY about three years ago. I've been slowly troubleshooting it ever since. I've taken it to the dealer twice. The first time, they told me I needed a water pump. I didn't think that was right, since my heat blows nice and hot in the rear zone. The following (last) year, I brought it back to the dealer again, and they said their computer "couldn't communicate with the 'HVAC controller.'" They said the controller isn't a part they could get, and I'd have to have it sent out and repaired. I figured I'd look for a used one first. Trouble is, I can't seem to locate anything called an "HVAC controller." Any ideas what this would refer to?

As I said, the rear heat blows hot. The front heat used to blow hot, then it would only blow hot occasionally, then it quit blowing hot all together. The mix door is operating just fine, I can hear it when I move the controls. Same with the flow diverter door. The air goes where I tell it to in both the front and the rear. I tried checking the coolant lines for blockage, but coolant flows through the lines immediately forward of the firewall freely. I'm thinking maybe the lines split just aft of the firewall to go to the rear, and the lines that go to the front aren't moving any coolant, and the coolant is just going through to the rear and back out the other line forward of the firewall (if that makes any sense).

Does anyone know any more about this system, and anything else I should check? I'd love to avoid having the dealer deal with this problem. Thanks in advance!

-Dave

 

No one?

Any ideas or additional information at all would be greatly appreciated.

-Dave

 

It sounds like your crappy dealer needs some attention - Dexter... LOL

Your logic is correct. The heat is there and the simple fact is that there is a mechanical failure somewhere related to whatever flapper, panel, or whatever blocks or allows the hot air to flow, divert, whatever you want to call it. WHETHER THERE IS AN ELECTRONIC OR COMPUTER RELATED ISSUE IN THE CONTROL OF THIS SYSTEM ON YOUR VEHICLE- I DONT KNOW.

One of the main points of this post is to inform you I was goofing with some of the internet features on me new TV, the YOU TUBE on in particular, and there are some very good informative QUICK videos out there today. I saw one this morning where the guy poped the trim/housing around the radio and a/c control area and quickly accessed some good stuff. one of the reasons I have to watch these vids is the whole science behind all the dash plastic just bewilders me... LOL but the guy opened it up and it was a simply plasitc gear on this car that was off track - Which was controlled by a CABLE. In a car back from 2000 this is probably the case I would suspect.

Good luck..

Its sad to see, but the repair scam days of the 70's appear to be on their way back in with the limited new car sales diminished by high credit requirements. Disturbing.. I water pump either PUMPs or not. It either leaks, or not. Anyone would realize that there would be more serious implications. disturbing indeed. And no one tell me its third party rabble I did not hear, or Poster converyed incorrectly, or whatever to defend them..!!! The funniest part is these are RETARDs trying to fool the American public and they dont even have the sense to come up with semi ligit lies and BS... And I DONT CARE WHAT ANYONE SAYS. I have had enough run in with dealers over the past five years to know.

 

Thanks for your response.

I'm surprised that no one in a Suburban specialist thread knows what the dealer is referring to when they mention the "HVAC Module/Unit". Can anyone at all help me out with this?

-Dave

 

UPDATE: A couple days ago, I randomly decided to try the heat since it was 40 degrees out. It MAGICALLY worked, and worked well! I had full temperature control, as well as air flow control. I moved every setting to every possible combination, with and without the rear heat on (which has always worked fine, no problems), and it continued to pump out nice hot heat. I tried again after work, and it still worked fine. The next morning, however, it stopped working, and now I'm back to the original issue.

Again, if anyone could tell me where to find this HVAC Control Module or whatever it's called, and what it looks like, I'd appreciate that. Is it the unit that includes the control *****?

-Dave

 

Dave did you get this problem fixed?

 

Intermitent problems are usually a bad connection some where. Many are where the connector pins are soldered to the circuit board. This can be a stress point.