IT'S GETTING HOT IN HERE!! - 2000 Buick Regal HVAC heater always on FULL BLAST!

05-24-2011, 01:02 AM
Hello everyone,

First time post. I have looked around and haven't seen this problem yet, so here goes. I have a 2000 Buick Regal LS. This problem used to be intermittent but has gotten to the point that I never see a "normal" operating state from my HVAC controller unit, so I need to get it fixed. The problem is that when I turn my car on the controller comes up completely blank except the 4 red lights on the passenger side climate control. The heater then (at the same time) turn on FULL BLAST and is stuck in the 90 degree setting (hottest possible). I got to the point that I pulled the high fan fuse just so I didn't die of overheating...

Today I tried to replace the actual controller unit with a refurbished unit I bought off of ebay. Unfortunately, I had the same result with the new controller...No display at all, but all red lights light on the passenger side climate control. My thought is that the issue is much deeper than a vacuum line (although I haven't checked them yet) or even the controller unit. I've checked all the related fuses and they all seem to be fine. Could this be a computer issue? If so what is the fix? Any other thoughts would be very welcome, even if they are only thoughts w/o a solution.



06-08-2011, 01:56 PM
is this the CJ2 auto climate control, or the CJ3 dual zone manual controls?

jake richmond
10-22-2011, 09:02 PM
I have same problem with a 2000 Buick Regal LSE - Auto Climate control with dual ( passenger and driver control). I took it to a local shop and they fixed a vacuum line and it worked for 2 days. They thought it was the control module, then. I replaced it - same symptoms. I took it to a GM shop. They said it was the HVAC control module... I asked about the actuators and they said they were working. I replaced the HVAC module from a better source. It still does same thing. I have pulled the fuse and sometimes it will reset and work for a short time (less than an minute, usually). If I try to change settings, it will go eventually go back to situation that the original post describes. There is approximately 12 volts at the fuse.

I think it may be an actuator, but do not know which one or part numbers. It could be PCM.

Cruise control will only set for a short time(seconds). There is approximately 12 volts at the fuse. This is a recent problem, also.

Tech II
10-23-2011, 11:13 AM
Has to be dual if he has a passenger side control.....

In addition to the control head, this may have a "programmer".....don't have a schematic to check......

07-11-2013, 03:45 PM
I know this is an old thread, but my 2000 Regal GSE has been having the exact same problem for the last 3 weeks... I have already posted an explanation of the problem on here:

I have tried re-setting the HVAC control by pulling the main HVAC fuse (passenger 15A) for 30 seconds - no change.

I also read somewhere that disconnecting the negative battery terminal for 20+ minutes may reset the HVAC control unit, but nobody has commented about that on my posts. Before I start taking apart the dash, or God forbid taking it to a shop/dealership, I would really appreciate if anyone could offer any insight.

And yes I do have the auto dual climate control.

Thanks in advance.

12-06-2013, 08:11 PM
I have a 2000 Buick Regal with the same exact problem. It started intermittently, and I've also had troubles in the last several months with the cruise control (which someone else mentioned in a similar post).

I currently have the 4 red lights on the climate control, and I have a dual passenger control.

From another thread, there's a possibility that the ignition switch is the source of the problem (?). I'm not sure, but a DC voltage reading on the HVAC fuse located on the passenger side, does only read around 8V instead of 12V or 13V, so perhaps the ignition switch is a culprit.

Anyone else know more yet?

12-13-2013, 08:54 PM
I'm following up on my previous reply above. I fixed my climate control. It turned out that the main issue was the Ignition switch. I bought a new one from Amazon. It was a bear to replace but all is well!

While I was at it, I also replaced my turn signal/cruise control/hi-beam control arm because the hi-beam switch had broken a year ago. For that task, one video I saw showed that you had to remove the steering wheel in order to replace the turn signal control. Nope. It was somewhat difficult to replace the part but you can use a wrench with a Torx bit to get to the one screw that is in a tight spot that would normally require the removal of the steering wheel to access.

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