The display of heat, location of air flow, temperature and fan flickers and changes on its own. Sometimes it works fine and blows out nice warm air. Other times it goes out completely and I have no control over any of it. It will just blow cold air. If I turn the head lights on it sometimes makes it go out completely. I have had the relay switch changed out and that was not the problem. I live in Northern MN and I need my heat and I can’t afford to buy a new vehicle. Any ideas or suggestions?
This is likely a poor connection to the control module. I assume that you are talking about an lcd electronic display? You may also have a voltage issue due to battery problems, grounds corrosion, or bad alternator(voltage regulator). What year is this truck/car?
It is a 1988, I believe.
Yeah those are known to go bad. IF you just need heat, you can have someone go behind the glove box and close the heat door, and tie it closed. This will take the display out if the picture and keep your heat on full time.
The only way to really fix the problem is to replace the electronic heater/AC control display unit.
Thanks for your ideas/suggestions, we’ll give them a try and see what happens!