2nd Gen Non-Engine/Transmission Defrost vents only blowing

[wyatt1672]

My 01 vents blow only through the defroster vents.

Worked fine one day then did not the next day.

Only ifno I have that may be a factor to the problem. It was parked by a tree for 2 weeks. Alot of debris feel on the truck, paticularly some type of seed a little smaller than a pea.

Ideas on hte problem?

Ideas how to fix the problem?

Would the difficulty factor of the repair make it worth having a mechanic do it?

 

[PVanderlugt]

Hvac in these trucks is vacuum operated, with a default to the defrost position. You are not getting any vacuum to your controls. 1. pump quit,2 hose came off/vacuum leak 3. not sure where you are in GA but i know it has been cold, moisture in the system and froze? one particular trouble spot it right underneath the windshield, drivers side in the engine bay, there is a couple of "T" 's that have a tendency to work loose, dry rot off.
Pete

 

[wyatt1672]

Thank you

I will begin by checking the hoses, then the vacuum pump. I dont think it was the cold. It happend before the winter.

 

[JLandry]

The HVAC selector switch on the dash sometimes go bad.



John L.

 

[Missouri Mule]

Check the Vacuum line where it goes over the engine into the passenger side firewall/cab it sometimes gets melted on the exhaust manifold.



When mine did this it was a pinched line under dash. I had re-routed the vacuum line going over engine so it wouldn't touch the exhaust manifold earlier.

 

[Fireman Dave]

Mine failed in the same spot as Missouri Mule's this past summer. It was a real challenge to find it - and reach it - behind the dash.