I have spent A small fortune on my car and still having problems, have new water pump, new oil switch, and A complete tune up , now my heat is acting up. I have A 96 bonneville se and my heat comes and goes , the fan works perfect the only problem is the air goes cold, I can play with the temperature **** and get it to start back heating but it will go back to cold air until I fiddle with the controll **** again, hope someone can help, love my bonneville but I'm going broke. THANKS[/list]

Do you have the automatic temperature control or is it a standard heater/air conditioner unit?

IT IS A STANDARD UNIT, I HAVE A CONTROLL **** FOR THE FAN, A **** FOR THE TEMP (COLD OR HOT), AND A **** FOR THE A/C DEFROST ECT. THE **** THAT I FIDDLE WITH TO GET IT STARTED BACK HEATING IS THE TEMP. ****

It could either be a "blend" door or "solinoid" for the door! I can't remember if your system is vacumn assisted or mechanically assisted. Either way, something is amiss with the heater box doors I think.