finally time to get around to fixing all the little stuff ive been putting off, just discovered my heat seems to be stuck on the wind shield defrost vents. Anyone know what controls the vent switch, is it vaccum actuated?

 

Yes it is vacuum controlled. Up on the cowl above the engine and turbo runs a hard vacuum line that cracks pretty regularly. I would start there. The hard line goes into the firewall close to the inlet and outlet of the heater core.

 

thanks ill check it out, Ive had a vaccum issue with the 4x4 that I solved with the posi lock kit but didnt fix the weak vaccum, might be the same reason my cruise recently stopped working

 

I really recommend finding a shop with a smoke machine and have them smoke the line. It'll make it very easy to tell if and where it's leaking and save you hours of hassle, You could still fix it just have them find it. If there isn't a leak you might look for a possible failed vacuum pump!

 

thanks ill check to see if the vaccum pump is working, I remember when I was converting the 4x4 over to the posi lock kit the vaccum seamed really weak, enough so that I would find it hard to believe it would acuate the shift fork for 4x4. Is there a vaccum resivior that could be cracked too?