need help my whole unit is stuck on defrost ?? what could be the problem?

[wardstang94]

everythings stuck on defrost? whats the problem

 

[revhead347]

All the valves under the dash are vacuum controlled, and the default when you have no vacuum is to defrost. You probably have a vacuum leak. The vacuum line that goes to the AC controls is a small line, about 1/4" diameter that runs down the firewall from the vacuum tree on driver's side inner fender to the passenger side of the vehicle. Usually that's the line that gets a leak in it.

Kurt

 

[wardstang94]

so do i just replace that? and see if it works? cause last summer it did the same thing and i took apart the dash and stuck my hand back there and then it kicked on to vent. but i let it set for winter and its doin the same thing

 

[revhead347]

I would look for the vacuum leak specifically. One of the lines is damaged. it could also be under the dash. All the vacuum lines under the dash are color coded.

Kurt

 

[wardstang94]

okay thanks.

 

[HISSIN50]

The vacuum line that goes to the AC controls is a small line, about 1/4" diameter that runs down the firewall from the vacuum tree on driver's side inner fender to the passenger side of the vehicle.

This is where you should start looking. It's also the easiest.

The line is hard plastic and cracks. If it looks ok, examine the boots in the line. It can crack right at that plastic-line-to-rubber-boot junction.

 

[revhead347]

It's funny, this exact same problem comes up at least twice a year on this website.

Kurt

 

[Adam95GT]

yep easy fix.