94 dual heating climate control problems

I have a 1994 Park Avenue, I took the car in to have the battery tested and terminals cleaned, after I got the car back, I had no heat just nice cold air, and a blinking temp on the Climent Contol.... Then nice hot air then cold again. I did notice when I bought the car the battery was dead and charged up, and it did the same as it was doing now, but I seemed to correct it self.. Does anyone know how to get it reset?

hi-i have a 95 park with the same problem about 30 seconds after you start the car the temp.starts to blink on the climate control. So I pulled down the glove box and watched both blend doors go from hot to cold back to hot again. (I have it set on hot). This happened after I disconnected the battery cables to clean them also. It has been about four months and it has not reset itself. Once the temperature stops blinking, you can adjust whatever temp you want just like nothing is wrong.I hope someone has some suggestions. Ruffo66

check your oner's manual, there's a reset procedure I think

I'm getting the blinking on my 98 LeSabre. It seemed to be related to the drop in outside temperature from the ambient sensor. But maybe it's related to the positions of the blend doors for driver and for passenger.

You may ahve clued me in on the problem. I'll have to check to see if my lower door is connected right. I had replaced the programmer last summer.

Sometimes when it's 40 or above the blinking doesn't occur. I also have the vent light still stay on, even though vent doesn't seem to be selected. Everything else seems to work fine. I'm always reluctant to dig into something when it's still working; I often end up with something not working once I start into it. I like heat in the winter here in the Midwest in winter.

When the climate control is blinking, it is indicating a fault is stored. Sometimes this can happen when the positive battery cable is disconnected first. Try disconnecting the negative cable first, and wait for ten seconds, then turn the ignition switch to the “on” position to drain any residual power from the system. Turn off the ignition and reconnect the negative cable. Sometimes this will work on the first try, and other times you may have to repeat the process several times. On 1991-92&93 models, you can reset codes using the controller. 1994 & up require a scanner, or you may get lucky using the procedure above.

Remove negative cable first and drain power.
Who would've thunk to try that!!!

I took my positives off to clean them to be sure crud was not built up between the double contacts. I think I did take them off without removing the negatives. I had cleaned both several weeks earlier. (I'm well aware of not touching anything to ground while tightening postives if negative is still connected.)

I'll try that tomorrow.

BTW: Is there any other cause that would give occasional blinking and not every startup? The vent light stays on sometimes and just goes off after a while.

you should always remove the negative first when disconnecting the battery.

OK . . . I have this same problem, and it appeared after I had the starter replaced by the local dealership, but I had no idea how the two events could be connected. I'll try the negative cable. If that doesn't work on my '94, since it requires a scanner, I'm calling Payne Pontiac and asking them to do the reset for free. I don't know if they'll do that, but if they caused it . . . .