Well my truck's heater is acting up, when you start it, it buzzes for about 20sec then when you shut the truck off it does the same thing for a little longer and every so often the heater control trips out and starts going on and off pretty fast by itself, The truck is an 88 Gmc regular cab. Any help is very appreciated.
Thanks,
Dave

My friends 94 was doing the same thing, he brought it in a few weeks ago to get the AC fixed, and now it does'nt do it anymore. I beleive its a solinoid that opens and closes a vent.

Jeff

That makes sense because my vents are always open on the passenger side, just never made the noise, it guess thats a motivator , thanks for the help,
anymore advice appreciated,
Dave

Yeh i still need a few ideas on what it might be. Come on, someone else musta had a prob with heater/ac acting up.
Thanks
-Dave