Stupid Heating Controls
 

i cant figure out why my heating controls on my 94dodge 3500 quit working. i can control the speed of the fan and the temp but not the directon of the air can anyone help me with this problem.

its a vacuum line problem. did it default to defrost?

^^^^ x2. Sounds like you lost your vacuum feed.

well awile ago it stopped blowing cold air so i figured it needed recharged. then the past 4-5 months when i have it on another control it always goes to winshield defrost everytime now i cant even get it off defrost:argh: like i always say i hate my dodge but love my cummins

Yeah you've lost the vacuum feed to your panel. Look for a black plastic line going into the firewall on the passenger side near where the A/C lines pass through. Follow that along the rim of the firewall over to the driver's side and check all of the connections. Mine came off a few times while working under the hood and I didn't know it.

If it's not off there then check at you control panel. If it's connected there then it's off behind the dash somewhere.

so when i fallow it to the driver side do i have to be looking in the engine compartment?

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if it were disconected somewere under the dash were would it most likely be

yeah under the hood.

There isn't really a "most likely" place if it's off under the dash. IIRC you can't even really see the line from the inside without at least taking the glove box out. You just have to take your time. Start outside though. I bet it's there.

well i look at it tonight and see if i can find anything

You'll find it. There is a vacuum T just above the brake booster. Mine always came apart there.

Also check where the line hooks to the vac. pump. Thats where mine comes off when I change the fuel filter. Like the others have said air will only come out the defrost if unhooked.

Does your ac clutch cycle? If not you might check your horn fuse (20 amp). Its also the fuse for the ac clutch.

i dont know if it does or not cycle i havent really noticed ill check the fuse also and see what i can find

Does your truck have cruise control?

My dad was having the same problem with the A/C and he found that the vacuum line from the cruise control had a hole in it. He replaced that part of the line and Bingo problem solved.

well i looked at all the lines in the engine compartment and they look fine. (first) does the truck have to be running? (secound) my cruise has never worked since ive owned it but the heatong control;s have

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i started the truck and now it works on recerculation and the face setting but anything that has to go to the feet automatically goes to defrost and when i start the truck it goes to defrost nomatter what setting it is on

You still fightin this one.

well the ac still doesnt work but i can get it to recerculate and everytime i turn my truck off then on again it defalts back to defrost

I know you said you checked the lines and didn't find any problems, but this really sounds like a vacuum problem.

well whats the best way to track a vacuum leak

Any progress?

Getting Shut down , Thread starter can reopen it if they wish ,

assuming issue has been fixed

well i got the a/c to work by jumping the clutch on a toggle switch but the damn thing still defalts to deforst every time the truck is started. and cant find any vacuum leaks

Any luck yet?

Since we haven'theard anything, we will assume that this problem is taken care of. If not the owner of this thread can reopen it at anytime.