poughkeepsie

When turning my A/C to max air i hear something like a vacuum leak and also going around 55 or so it will also change over to defrost. Can you purshase just the vacuum switch and if so what is the name of the part and where can you locate it at. Its is a 1995 ford f150 !

Thanks

wde3477

the typical suspect on my gen8 (87-91) is the white vacuum line going to the recirc damper actuator near the blower motor in the engine compartment. The section in the engine compartment will generally be found crumbly or brittle. Can generally splice in a section of regular rubber vacuum line.

poughkeepsie

The hiss comes from the switch when you select max air.......anyone know whats the name for the selctor switch ?

dewman

I don't know the official name for the switch. But, are you sure it's a vacuum leak?

This Memorial Day, I was driving to my sister's house and had the a/c on max and also had the cruise control on. Twice on the way to her house, the a/c switched to defrost and then back to a/c all by itself. On the way home, I had max air and cruise control on and it happened again, twice. I turned off the cruise control for the rest of the way home and the a/c stayed on max air, without switching between defrost and a/c. First time the truck has done this. I am thinking electrical issue, but I am not sure.

poughkeepsie

Pretty sure.....when i took the control panel a part and left everything hook up and turned the selector switch to max air thats when i can hear the hissing sound............. that a vacuum leak. Sounds like you also have a vacuum line leaking some where....

dewman

I was thinking mine was electrical, because it only does it when I have the cruise control on at the same time. And, there is no hissing sound while the a/c is engaged.