HVAC Control Head in dash--multiple issues (Mostly fixed)

[Jerrys1990]

No. The outside of the plastic connector body was melted. In fact, it was hard to pull apart because the two pieces had kinda melted-together in one place.

I would pull it apart to verify the actual contacts inside.

Might be helpful to put a voltmeter on the alternator output terminal and ground, to see if your electrical system is properly regulated.

Good idea. Sometimes the lighting flickers a little while running....I have a bad feeling about the alternator TBH.

 

[Jerrys1990]

VERY good idea, and yes, mine was behind the glove box.

This reminds me that I was going to update this thread by showing how to replace the three tiny lights that illuminate the control buttons. I have the lights--I think--but not the time or ambition to actually put them in.

I guess that'll have to move up on the priority list.

Schurkey, you're the man. I went to the yard today and found a 1993 HVAC head. It had a broken button, so I just swapped in one from the old head and cleaned the crap out of everything. It works perfectly now. The backlighting doesn't seem to work but hey....I'll deal with it later like you LOL! I also got a heater core from the same truck....I have a feeling mine is blocked. Flushing it showed very little flow and did nothing. For $15 bucks I figured "What the heck." Still need a thermostat though. Testing with everything running, the heater core input hose would get extremely hot as it should, but the return to the radiator was not hot at all. Thermostat issue or not, it leads me to believe there's a flow issue through that core. There should be a temp difference yes, but not THAT drastic. Anyway, thanks for the great tip about the HVAC head. Definitely an upgrade everyone should do with an 89-92.

 

[Burbonsurgeon]

If you aren't getting heat out of your heater core, try back flushing it. Disconnect heater hoses from truck. Hook one up to a tube of some kind so the crap coming out of your system doesn't stain all your clothes funny colors. Hook the other hose up to a garden hose and carefully increase the pressure until you get flow out the other end of the exit hose. Be careful because you can burst the heater core with to much pressure and that would really not be the thing to do.