Vacuum controlled HVAC question

[Agnem]

Must be PRTJ. Lady Moose has decided we are only worthy of air coming out of the defrost. I've troubleshooted it down to the fact that there is vacuum to the control knob, but it doesn't seem to be getting to any of the vacuum motors. I was wondering if there is a failure history I can rely on, or if I need to delve deeper into measuring the actual amount of vacuum or anything like that.

 

[towcat]

Must be PRTJ. Lady Moose has decided we are only worthy of air coming out of the defrost. I've troubleshooted it down to the fact that there is vacuum to the control knob, but it doesn't seem to be getting to any of the vacuum motors. I was wondering if there is a failure history I can rely on, or if I need to delve deeper into measuring the actual amount of vacuum or anything like that.

mel-
it's happened in my work rig. their solution was to replace the panel. it works now.

 

[Agnem]

That's kinda what I figured. I guess I'll be calling Stoner-Wade tomorrow.

 

[hoodshauler]

Dang it PRJ already hitting hard. Tanya Has left the Horse trailer hooked up now for two weeks said she is hoping the truck will think it is just another horse show.

 

[Double-S-Diesel]

Not quite sure where ya burnt the carpet, but the vacumm hoses from the switch run right over the hump against the fire wall. It is possible that they got melted. Ive seen it before, in my 92, PO cut a hole in the floor in prep for the turbo he never put on.
Nick

 

[ramon f350]

Calvin,
which panel are you talking about? the one inside the cab with the blower speed and temp controls? I have replaced all of the controls and switches on mine and i cant get all of the doors to close on mine. no matter what i set the control for I always end up with the defrost on. I discovered this on the way to Corpus Christi about 430 AM when the windshield started fogging up. Is there possibly some other valve or control I have missed that can cause this?
Thanks for your help
Ramon

 

[icanfixall]

The defrost mode is what all cars and trucks fail to. Its for safety. That way if you loose the vacuum signal you at least will be able to clear the windshield and see where your going. I had a problem with a truck I bought that didn't seem to have the doors closing off. So I started removing duct parts. I finally found what was wrong. A ladies wrist watch and a pencil had fallen down thru the defrost vents on top of the padded dash and was jamming a door open. Nice find both ways too.

 

[ramon f350]

I guess I need to make time to get in thereand take the ducct work aparty maybe I can find a rolex or something.

Ramon

 

[Agnem]

Not quite sure where ya burnt the carpet, but the vacumm hoses from the switch run right over the hump against the fire wall. It is possible that they got melted. Ive seen it before, in my 92, PO cut a hole in the floor in prep for the turbo he never put on.
Nick

Nick gets the prize! They didn't look melted, but they were. I fixed them McGyver style. cut out the bad spot, and used a piece of wire insulation as a hose to bridge the two pieces.