I have a 99 ranger 3.0 and tried the air for the first time yesterday,,, I was told by last owner it worked,,, after just a mile or so I was getting cool and then hit a bump in the road and air quit hitting me,, and was now going threw the defrost,,,, next bump and air is hitting me in face and chest again,,, next bump back to defrost ,,, anyone had this issue or know of a fix ??????????????

 

Sounds like the blend air door does not stay in the selected position. Try a search here on blend air door fixes and see what turns up.

 

searched here and got a few answers ,,,,then searched youtube and watched several videos on air blend door,,,, thanks to ranger pat for your advice ,,, will fix tomorrow if not to hot out

 

On page 3 of this thread, I battled my AC going from vents to defrost, but mine was engine vacuum dependent. It seemed to get better or worse depending on outdoor temps, or if hitting a bump moved the vacuum line against something that helped plug the leak temporarily.

https://www.ford-trucks.com/forums/1...t-vents-3.html

 

Yeah I pretty sure mine is caused by a vacuum leak,,, been a little under the weather so I have not messed with it yet,,,,, also just replaced my DPFE sensor and have some vacuum issues there two and the diagram on under the hood is not the best,,,wish I had some pics of the 3.0 (1999) vacuum hose routes,,, so if anyone has any pics of 3.0 vacuum lines please post them here a few pics would be a lot better than the useless diagram under the hood

 

I'd say take the 15 minutes and pull the passenger inner fender. The vacuum lines for the HVAC go from the engine on the passenger side of the intake, through a check valve to the vacuum canister. My canister was under the battery and above the inner fender. Then out of the vacuum canister, a hose goes through the fire wall to the controls. Then one hose comes back through the firewall from a tee on the recirculate or fresh air selector door actuator behind the glove box. It passes through the same bulkhead fitting back out to the engine bay to the heater core coolant shut off valve. Parts of those hoses are between the blower housing and inner fender, well hidden.

All of my hoses inside the truck were still like new. The leak is most likely somewhere in the engine bay, and every inch of the lines are visible without the inner fender in place.

 

Thanks Bigred for pointing me in the right direction,,,, the grey hose is hooked to the heater shut off,,,, there are four black lines all close together,, one from the can i think,,, one to the inside cab,, one to engine and fourth not sure about ,,, but all four are together and not hooked up,,,, just got to figure out which two hook together then other two is a no brainer,,,,,, I think its just trail and era from here lol,,, oh and all four are long enough to go any direction,,,, think i can figure it out pretty quick,,,thanks for the help