Hello all. I have a 1991 Buick Park Avenue. I have a problem with the heater a/c control (ACDelco Part #16148154). For a while the heat, A/C, and defrost would periodically go on and off, not by itself but when I was using one of them. I figured there was a short somewhere because everything worked, just not all the time. Several mechanics have looked at this and have been unable to fix the problem or find the short or see if there were problems with the contacts to the buttons. Next I tried to replace the heater control and was unable to find one. Why is this part so hard to find? A Buick Lesabre 95-05 has come with a very simliar heater control, is it possible to use one of those in a Park Avenue? Has anyone encountered a problem with the heater control similar to this? Please let me know. Thanks everyone.

Could you elaborate a little more, on what goes “on/off”? Is it the fan, compressor, AC Control Panel, or does everything go off/on at the same time? Do you have Auto Climate Control (Digital Display - ACC) or the manual system?

I believe the problem is with the unit itself, the compressor and blower work, they just can't be triggered to turn on. I have the Manual system, and boy is it a hard replacement part to find. I may have found a replacement unit for about $55, hopefully the guy is for real. Have you had any experience with the manual system failure or trouble with the electrical contacts?