Recently had the AC system serviced & was nice & cold, but when I went to raise the temp a few degrees today it went hot & stayed there. Turned it on and off several times & it came back to normal. Thought I would check it out again tonight. It was nice & cold but when I raised the temp again it went hot and stayed there. This is heater air hot, not just lack of A/C or outside air temp.This is the automatic HVAC system. Is there a temperature control door that might be stuck?

Does the temperature display ever blink?

No, the display does not blink. You can move the temp shown on the display all the way up & down and the fan speed works, but I am getting maximum heat all the time & we have a few hot days coming up!

Well, you're stuck because the 96 does not have on-board diagnostics. The dealer is the only one who can to the diagnostics.

But we can check a few things.

When you are receiving hot air, does the compressor turn? What happens if you dial the temperature back down to 60 degrees?

Mine did the same thing except the service thing. One day I went to turn the temp down and next thing I know it'* 90 in my car, hot air was coming out with it off as well. I shut it off and hit auto a few times I think it was 5 times but it came back haven't had a issue since. Might have just been a coincidence though.

The compressor is running, but all I get is full hot regardless of where the temp is set. I wonder if it'* and actuator that controls the hot/cold mixture.
Just like you said Jr Faust, I hit the auto, off, & A/C buttons several times and it finally seemed to come back to normal earlier, and I should have left it alone when it was cold, but when I had another look at it tonight I adjusted the temp upwards and now itis stuck on max hot again.

On my '92 SE, I know that you can actually *see* the heater core actuator in action once the glove box is completely removed (an easy job).

Perhaps that'* a place to start looking.

Agreed; sounds like you have some sort of problem with a mixing door in the ductwork possibly getting hung up on something...

Hey Fuddy. The temperature numbers were blinking for a while. What does this mean?
If this means that I will need a new control panel unit I will be thrilled because I will get one from the wreckers & just plug it in.
I have spent hours under the dash and cannot get to the air mix door. It is supposed to be controled by an electric motor, but seem impossible to get to without removing the whole dash. I think the air bag system makes the whole thing more complicated.
Thanks for your input guys.

It'* possible that the passenger'* airbag makes access to the airmix actuator a bit harder than on my car, that only has the driver'* airbag.

However, you may want to try to remove that lower plastic panel on the passenger'* side, just above the passenger'* feet, if you haven't already. Then you might be able to reach the actuator from below with your hand.

Take a look at this photo, I took it while working on my car. The heater core is that radiator on the right, normally there'* a black plastic case that covers it, with the airmix motor mounted right on top of it. That metal rod just above the heater core, controls the airmix door. The motor rotates an arm that connects to that rod. You might be able to reach it from below.

My car is a '92, so yours may be a little bit different, but I think the general design is the same. Here are the links (you may need to open a new browser window and copy&paste them):

http://www.geocities.com/uri14979/100_0647.JPG
http://www.geocities.com/uri14979/100_0645.JPG

Hope this helps, let us know how it goes.