I have one of the coldest blowing AC's I've ever experienced in a truck...but it's got a problem. If I put the dial on "max" it'll work fine, unless I'm giving it some throttle. The second that I give any kind of accellerating throttle the a/c stops blowing out the forward vents and starts blowing through the defrost vents and won't come back until I'm deccellerating.

I asked around before and I was told that this was a caused by a vacuum leak. Where would the leak be?

Thanks guys!!
Also, I have a serious problem posted in the "engines" section...if you wouldn't mind hitting that,too. Need help!

 

Yes it's a vac leak. I'd pull the HVAC unit and look behind there for anything obvious or behind the glovebox.

Link us to that motor problem, I don't want to search for it... there's tons of threads in there.

 

I know that some Ford A/C systems shut off the A/C when you hit the gas hard. It makes it easier for the car to pass and the A/C comes back on after the manuever. I am not sure if our systems have that 'feature' or not but it may stuck and comes on every time you hit the gas. Good luck.

John

 

Almost all vehicles shut off the a/c compressor at WOT, but that doesn't change where the air blows out of the vents. Like hit man said you have a vacuum leak, or a bad vacuum check valve going to one of the cavuum motors that move the air mix doors.

-Jon

 

yea its a vacum issue mine did the same thing its a line that goes to under the dash close to the glovebox that connects to a arm to move from defroster to vent if u want a temp fix just pull the arm back and wedge it in. the line is a white line under the hood (right by the antenna) and runs to it you'll have a leak between the two




Daniel

 

On my 1983 F-150 it was the sliding valve on dash (A/C Normal, Max A/C,
Heat Floor, and so on), repaced it and it was fixed.

 

I have the white line on passenger side under the hood that is falling apart. A/C never used to cut off under throttle but does now. That is only problem I can find. How do you replace that line or "splice" into it. Where would you purchase that size of line. It goes into some conduit on one side then some rubber gasket toward firewall. Any help would be great. 1996 4.9 5speed 2wd 205,000miles