I have had a number of different issues with the climate control since I bought the car. I am hoping somebody more mechanically inclined can tell me what is up. The first problem I had was the climate control going completely haywire. It was beeping, everything would light up it would turn on and off as it pleased. took it to a shop.....guy claimed it was just corrosion on battery. said he tested it and alternator and both were good. Drove 500 miles back home, and 60 miles before getting there, it started up again. took it to the shop in town, bad cell, got a new battery. Problems still going on. took out aftermarket cd player, and put in the original radio. Problem solved. Now dual climate control doesnt work.
After the dual climate control was screwy I popped open glove box and can move the small lever in there freely after unjamming it....so, winter it goes to one side, summer it goes to other, between seasons its a pain. Ever since this problem arose, the numbers flash on the digital screen every single time I start the car. It blinks for about a minute whether or not I turn the system on at all. The outside temp number just blinks. I figured it had something to do with the dual control not working right. like a warning light.

Now. Winter is hitting the other day I was driving and notice the digital screen starts getting very dim, almost off dim. Strange. I tap it, it gets nice and bright again, then dims out. speed up, it gets bright, let off throttle, it dims down again. Keeps getting worse. Anyone have a clue what it might be?

No idea. I got problems with my climate control in my 90 Lesabre Limited. I was hoping to fix the wiring but never got to it. And the wiring schematics in the chilton book is all crazy I don't get it.

My head lights and all the lights used to dim while braking then light up while accelerating. But that was due to my fuse box hanging down by the brake peddle, also a short in one of the wires had burned off the coating so it is just a copper wire. Sometimes the whole dashboard would cut out. I kind of fixed it by placing the fuse box back where it should be and smacking it a few times until everything came back on. But now when ever I can I want to figure out the climate control problem.

I am going to try checking the voltages in my wiring then run some new wiring and going to check with the fusebox.

Update. Dimming was not related to throttle whatsoever. Just seemed like it the first time I noticed it, which was all too strange at the time. Bought used heater control off ebay for a good price. New ones run 500 bucks on rockauto. Used one works, just put it in yesterday, put in a new heater blend actuator, I think it is called, up in the dash behind glovebox/airbag. Started up the car, the screen is nice and bright, still flashes though. Something is still not right.....Any Ideas?

Your dimming lights were the LED'* in the display failing. Sounds to me like the flashing could be loose wiring, or a wire stripped and grounding out.

thanks for the thought. It only flashes at startup for a bit...The odd thing is, I used to start the car up and the numbers would flash on and off for a bit, blinking like a turn signal. They would start to blink almost immediately when the car was started, whether or not I turned on the heater unit. I always shut it off before I turn off the car. Now that I replaced parts, it has not blinked at all until I turn the heat on. Strange. I was just all up inside the dash, although I tried to remove as little as possible, all the wires LOOKED good. Doesn't really mean much, but I did not see anything that looked remotely questionable. I never did unhook the battery to reset everything though....hmm. Gonna go try that right now...just to see what happens.

Alright I cheered to soon. took longer to start blinking but oh it did blink. So. I opened glove box and watched that little lever as I cranked heat, then rammed it way down. It did not move at all. Gave it time, still nothing. The old blend actuator was bad, it was loose and moved freely, the new one is solid. So....Connection issue? Bad wire like you said, OR is there a fuse for that specific part I wonder? can at least check that and move on from there. Would assume its on passenger side, just a damn pain to get at that panel from what I remember.

Okay, yet another problem, which I have ignored for quite some time, that may explain this better? Even after I shut the heat or Ac off. Air keeps blowing out at a good rate at whatever temp I last left it. Running heat, shut it off, blows hot air out on the floor, same with AC. Blows cold on floor even when its off. Not sure why. Anyone have a clue?