Okay Y'all,
I was not sure where to post this but I figured I could not go wrong asking my fellow S-Crew folks. I have a 2001 S-Crew Lariat with an Auto Trans, 4X4, and a 5.4L engine. I purchased the truck a few months ago from a friend so I know it has really been well cared for. Anyways, the other day, cruising down the interstate, the A/C cycled from the panel vents to the windshield/defrost vents. As soon as I let up on the gas, it returned to the dash panel vents. Anyways, it did this a few times before I got home. The air coming from the A/C is always cool, so I do not think I have a compressor prob. Today when I drove it, it only blows out of the windshield/ defrost vents. It sounds to me like maybe a vacumm hose or a solenoid/switch has dumped on me. I was just wondering if anyone has experinced this before and might head me in the right direction. I am all for DIY repairs if possible. It is worth a try before heading to the mechanic, which I wil do later this week if I do not figure it out. Any help would be extremely appriciated. Thanks guys & gals. Chuck.

 

do you have a tradiational Heat and AC system or the climate control?

i would suggest posting the question in the HVAC forum. https://www.f150online.com/forums/fo...?s=&forumid=69

 

It is a regular Heat/AC System, not Auto Climate Control.

 

You probably have leak at your vacuum resevoir/storage or connections. It's behind the battery tray, actually attached next to the fender. Follow the lines going to it and make sure you have no loose or cracked fittings.

Good luck

 

I have heard of this problem from some forum, maybe it was this one...if memory serves me, it was either a problem with a vaccuum line or a control arm on an actuator located under that black portion on the dash over the vehicle hump.

TonyPTX

 

Most likely a leak in the vacuum line leading to the accumulator or the accumulator itself. It is a coffee can sized tank on the firewall or fender behind your battery like Canyon said.

 

Thanks for everyone's input. I will crawl under the hood tonight and see if it is something I can handle. If not, it is going to the shop tomorrow cause I am heading to the beach this weekend and need my A/C. :-) Again, thanks for everyone heading me in the right direction, and I will let everyone know how it pans out. Chuck.

 

Mine is actually box shaped...

 

Mine probably is as well, haven't looked at it lately.

 

Y'all were correct, it was the check valve on the accumulator (sp?). Thanks for all the input. I went ahead and had my mechanic take care of it as it looked like more than I had time or gumption to take on. :-) Back on the road and blowin' cold. Yippee.