02 f250 ps deisel 4wd. when i put the truck in 4wd the ac starts blowing out the front vent. first couple of times it lasted about a week and went back to working normal. now it blows full time out of the vent. the fan speed works and the on off works. its getting to be summer time real quick down south and i need to get this fixed

 

Hello reeko22 and Welcome to FTE!

Wow! That is one I haven't heard of. Did you just buy this truck or did it start this all of a sudden? I would suspect a problem in the climate control module if you have the electronic control.

 

What's a "front vent"?

If you mean the defrost, then there's likely a vacuum problem.

That invites two additional questions from someone with diesel F-series experience:

1. Vacuum source, if used?

2. Does the 4 X 4 system also use vacuum that might be leaking?

If you push MAX A/C, can you get 4X4? JK

Steve

 

Sounds like you have a vacuum leak in the 4wd lines. When this happens the vent system defaults to the defrost position. Start looking for the leak at the rubber lines connecting to the front wheels. If it's there, you may can just cut off an inch and plug them back on and have the problem fixed.
Joe

p.s. WELCOME TO FTE !

 

just started this hunting season, i have 160k on this truck bought it new after i sold my 99 with 140k on it. it is blowing out of the defrost

 

thanks for the help, the lines were dry rotted on one side and i clipped it and replugged.
I took it to a local 4x4 guy and it turned out to be a bad solenoid next to the vacuum pump. took them 30 minutes once they figured out the problem, cost 90$.
well worth it, since its been 95 + 90% humidity here lately

thanks again
richard

 

Sweet! I am in Gulfport MS doing some rebuilding for a charity (didn't mean to break my arm patting myself on the back there) and had to go into 4x4 for a minute or two. My A/C did the same thing. I was in sand in 4x4 and it hopped really bad like it does so I thought that the hop may have caused the problem but I tried it on the street later and it did the same thing. I thought it was some sort of thing to help keep....well, let's not get into what I started to think. You start to panic when you have 4 other construction guys in your truck and it is 90+ deg and your A/C quits working right. Anyway, I will check out the vacuum lines when i can. Reeko22 - was the solenoid for the 4x4 or was it for the vacuum system in general?

big

Oh, 2003 F350 6.0L psd for me.

 

was just the solenoid, my guy called the ford people, they tried to push the vacuum pump which was a buck fifty, good luck in gulfport im in n.o. doing the same

 

Thanks for the reply, Richard.
It is a real mess isn't it? We were just touring the beach/coast when I had the problem with my A/C and were simply awe struck at how destroyed it is - 9+ months later. Not that it will be a quick fix but it is amazing how much work is yet to be done.
I was just down for a week and am home now in NE Indiana where the temp has dropped to a daytime high of mid 60s. Quite a change for me. I have a fleece on now!
Anyway, good luck in N.O.

Big