heat blows cool air

I have a 94 Bonneville SSE and the battery is dying. It went dead on night and after recharged it the climate control light start blinking. Now the hot air will only work when the car is first started then light will flash and heater blows cold air. I thought the door might be stuck but it works when it first comes on, also if temp is on 60' a/c works fine. Does flashing light mean thermostat going bad.

FIrst, the easy things. I think the computer that runs the ATC was reset improperly due to the dead battery incident.. I suggest to disconnect the battery, and completely evacuate any residual charge by turning the headlights to ON for 1 minute , then reconnect the battery . (YOu will have to reprogram your radiostations ).
Tell if this changed anything to the heater problem.

I tried to disconnect the battery to reset the atc it did not work. The battery was disconnected for about 20min while I went to the store to buy another one. When I restarted same problem. So i took the climate control unit aloose to see if maybe the unit was bad, same problem; first heat then what sounded like a solenoid humming then no heat. Is there a way i can manually reset the ATC; or do you have any pictures/diagrams to show where ATC is?

After this, resetting the temperature control computer unit does not seem to be the problem now.
Look at Randman's post with picture in this thread:
http://www.automotiveforums.com/vbulletin/showthread.php?t=331680
mm.....well not exactly that ...this is about the ATC blower control.....

Since it worked before the battery died, the problem seems linked to that voltage drop...: there is a deflector door that mixes cold and warm air and it is..(in that model too, I think), positionned by an electric actuator....maybe that....

I do not have the electronic temperature control myself so I think Randman should kick in here and now ...Hey...Randman....????

OK Check THIS thread:
http://www.automotiveforums.com/vbulletin/showthread.php?t=181664

and this one...!!
http://www.automotiveforums.com/vbulletin/showthread.php?t=298431

The air mix door actuator is the first thing that comes to mind. Unfortunately, your 94 doesn't have the on-board diagnostics for the Electronic Climate Control. The last year to have this function was 93. Since the air mix door is such a PITA, you may want to consider taking the car to a dealer to have the ECC codes read.

The actuator has plastic (maybe nylon) gears that move a lever. It seems that these wear over time as shown by the number of similar threads on this forum. Mine was able to go from one direction to the other but not back again so it would appear to be working intermittently. Another thing to check is your external temp sensor. This would not cause the ECC display to blink but can affect the temp of the air. For instance, my ext temp read 168* most of the time. The only way to get heat was to set it to 90*. The next step down (85*) would blow cool air.

Thank for the help with the heat problem i will try to locate the actuator first thing in the morning. I had another problem last summer with replacing rear shocks will look for threads on site thanks again.
-Will

I can tell you where it is:

http://img.photobucket.com/albums/v155/randman1/1993SSEi/DSC01064_edit.jpg

http://img.photobucket.com/albums/v155/randman1/1993SSEi/DSC01066_edit.jpg

If you take the black part of the glove box apart you can usually see it between a horizontal piece of steel and plastic duct. You can observe the action of the lever by going from full hot to full cold. The swing of the lever is about 90*. Some people have just manually moved the lever into the full hot position temporarily.

Unless you know for sure that it is your problem, I wouldn't go taking your dash apart. Get the codes read first. It may save you a ton of trouble.