When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
All the different functions of my climate control have always worked of my 1981 f150. Last fall one day it got stuck on defrost and won't go to vent or floor. I took my dash apart and it's a little confusing but none of the vacuum valve things do anything when I move the handle with the motor running. Does this mean I have a vacuum leak somewhere? The temp control function still works. I also don't hear the distinct hissing noise while moving the lever.
Should this loose vacuum line be hooked up to something?
That thing on the firewall is a vacuum tree, it takes one line and splits it into two. The line farthest to the right on the tree is the vacuum supply that hooks to that elbow fitting down on the intake. Then you have the middle one that is hanging loose, then the one farthest to the left. Trace the farthest one to the left. Does that line run over to a vacuum can and a tee over near the pass side hood hinge? It should also make it's way through the firewall near the pass side hood hinge. This is your vacuum supply to the dash controls.
If I were to guess, that line laying loose is sucking air and robbing the line farthest to the left of vacuum if that left line goes to the dash controls. Plug that center line with a bolt, I do not know what it originally went to .You might have to reset your carb after plugging the line, it will not be sucking all that air like was before.
That thing on the firewall is a vacuum tree, it takes one line and splits it into two. The line farthest to the right on the tree is the vacuum supply that hooks to that elbow fitting down on the intake. Then the middle one i hanging loose, trace the one farthest to the left. Does that line run over to a vacuum can and a tee over near the pass side hood hinge? It should also make it's way through the firewall near the pass side hood hinge. This is your vacuum supply to the dash controls.
If I were to guess, that line laying loose is sucking air and robbing the line farthest to the left of vacuum if that left line goes to the dash controls. Plug that center line with a bolt, I do not know what it originally went to .You might have to reset your carb after plugging the line, it will not be sucking all that air like was before.
That was it! I was thinking it had something to do with vacuum. Thanks for the help!
Look at the vacuum tree on the manifold. It appears to to have an open nipple just above your loose vacuum line. I bet that is where that loose line was originally connected.
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.
