Reverse type Heater problem

[merlinof2]

Hi Folks,
Have a 1998 Jimmy SLT 4Dr 2WD. 135K miles. Love the vehicle, it's been great. Developed an odd problem I can't seem to track down.
Ran electrical system (battery) flat on a camping trip. Got jump started, all ok, except heater blows hot air constantly, (and I mean HOT, no flush needed). It fixed itself in about 3 days, don't know how, didn't question. Ran system flat again working one weekend and same thing happened. But after 3 weeks I'm guessing it's not going to pull a Mopar miracle. I'm guessing it's some sort of sensor gone amuck, but for the life of me, no manual anywhere details the internal Climate Control Heat/Cool sensor description or location. No electrical diagram shows it and mechanics I've asked give me the scratch of head puzzled look routine. I've found the ambient sensor, (on bracket by radiator), but where o where is the internal temperature sensor??? Is it the heater core sensor??? PLEASE NO!!!.... and has anyone else had this happen and if so, what was the remedy. Thanks everyone for your time.

merlinof2

[rlith]

The sensor on the rad support is simply for the Overhead Display. Now do you have the computer Climate Control System, or just the regular? If just the regular it will be more related to vaccume not closing the blend door properly. If it's computer controlled system. The HVAC moduile will need replaced.

[merlinof2]

Originally Posted by rlith

The sensor on the rad support is simply for the Overhead Display. Now do you have the computer Climate Control System, or just the regular? If just the regular it will be more related to vaccume not closing the blend door properly. If it's computer controlled system. The HVAC moduile will need replaced.

First, MANY THANKS for your help. This has been frustrating, and I used to build my own super stock dragsters when I lived in Maine. (just never paid attention to the heating/ac systems in them)
I'm assuming "regular" as it's a dial that I set the temperature with. No LCD display. Hmm, I've had less luck finding a vacuum layout than an electrical layout showing sensors... Should I guess old, broken, or disconnected hose here? And the "blend" door, is under the dash behind the glove box I'm assuming.

merlinof2