The cold snap we have been having the past few days has moved my heater up on the list of priorities. Everything works fine except that when I move the heater lever to "Floor" it comes out the defroster. Everything else is perfectly normal.

Where should I start? I searched but to no avail.

 

What year truck? Does it have ac?

 

you have a vacuum leak. defrost is default setting when the controls get no vacuum.

 

I agree with Tom..

For reference:

 

1990 w/ A/C

Even though the Vent position works?

 

Found this.


I took the radio out and the heater controls loose. The defroster/floor actuator is moving. There is a plastic piece on the end that used to attach the actuator to the door. It must have broke.

Has anyone had this happen before? How big of a job is it to fix it? I think I might just go buy some wool socks.

 

Any Ideas on what I have to do to fix it? Does the whole heater box drop down or do I have to pull the dash apart?

 

You can get into the heater box by removing the glove box, you will then see the rear cover of the heater box which come off with a few screws.

 

The actuator and flapper is closer to the drivers side. How do I pull the flap out to put a new one in? Is the flapper even a serviceable part (can I get a new one)?