With the weather getting colder, I fired up the Heater/Defogger but no matter which option I select(BI-LEV, VENT, HEATER, DEFOG), it does change the amount of hot air coming out. The air always comes out of the vents(and a little bit out of the defogger) no matter what setting it's on. The temperature control works, but the function selector does not seem to make a difference(except when you turn in from OFF to any other setting). Also, when I turn the car off, I sometimes hear a popping sound near the heater core. Any ideas on how to fix the problem?

 

guys, sorry I posted twice...i accidentally hit the button twice or something.

 

any chance you hear a vacuum leak around the ac/heat controls? chances are, your vacuum connector on the back has "dried out" and won't hold a very good vacuum whether you hear it or not. usually, the air will all go out the defroster vents, by default. anyhow, i'd get behind there and take off that vacuum tube assy. on the back of that selector switch, run you some vaseline inside the tubes (with a q-tip) and stick it back on there. that will usually help the problem. one suggestion would be to take your stereo out to do this (makes it easier) and another would be to lay out a rag over the tunnel area so if you drop those fasteners, hopefully they won't go too far.

KAM

 

Ok, I checked the vaccum tubes on the back of the controller, they seemed ok, but I put vasoline on them anyway. The problem is: No matter what selection I have it on, air comes out of the main vents at the same force, even if I have it on DEFOG or FLOOR(Heater). Any other ideas?

 

It's a problem with that vacuum thing. One way or another, the little doors that direct the air to the correct ports, aren't getting vacuum.

Is the vacuum supply line to the little switch hooked up properly under the hood?