Heater Controls Question

[84GNwith87eng]

Well I had my heat fixed recently, (new heatercore/hoses), and it was running really well. My car only blows from defroster because something is ****ed up with my box, but anyways...

Now I can feel heat from the defroster, but my low/high settings don't work, pretty much making my defroster worthless. Do you think my heater controls took a crap? What else could be causing them to fail? (if its not the controls)

Thanks

 

[Topjimmy]

There is a vacuum switch on the back side of the dash control unit. This switch has a diaphram inside that fails often and defaults to the defrost mode. A telltale sign that this is your problem is a consant hissing leak when the control is set to heat or vent. The switch is cheap and should still be available from GM, seperate from the dash control.

HTH - Jimmy

 

[DMan]

Yep, Topjimmy's got it.

What also happened to me a while back was that the temperature control ARM connected to the cable on the heater box snapped.

Remove your glove box and you should be able to see the control arm and cable. Check to see that it moves when you move the control on the dash.