In my 1997 the fan only blows through the defrost and the foot blowers. Even if I change the mode it won't come out any other vents.

I read online that it's all vacuum operated and there is likely a vacuum leak, which causes it to only work in default mode of defroster and feet. Makes sense.

So I removed the dash and behind the mode control **** are the 5 vacuum lines going south. All are on and in good shape. I look under the dash and all lines are connected and in good shape. I don't hear any vacuum noise either. I do however lose two of the hoses, black and green, behind the vents and can't tell if they are connected.

Can it be anything other than a broken or disconnected line? It just seems so odd a line would disconnect or crack. When I manually work the " actuator?" that the lines connect to, I can change the mode and it blows out of different vents.

Thanks for any help,
Ryan

 

Just found this thread with some good info

https://www.dieseltruckresource.com/...er+vacuum+leak

Maybe I'll look under the hood too?

 

Most likely out under the hood drivers side by the cowl vac hose came off. There is a T between vac pump and brake booster, check the hose there. If oil from vac pump gets into these vac lines they will swell up and come loose. Replace any hoses that are soft and swollen from oil.

 

thanks for the reply, I'll definitely look there. I did just change my fuel filter, so I could have knocked something off.

 

Found it. Knocked a line off when doing the filter. All is working. Thanks again

 

Mine is doing the same thing but all of the hoses seem to be connected and not leaking....any other ideas what it could be?

 

Where does the vacuum line connect under the dash? is it easy to get to. I have one that someone ran a new line that has come loose to where it was connected under the dash.

 

The lines are very easy to get to. You have to take out the dash partly, by removing the two screws holding the ashtray and two screws holding the cup holder. It will now come out with a little pull, but remember to pop off the wires to the cigarette lighter and 12v socket.

Once thats off unscrew the 4 screws holding in the 3 **** controls for AC/Fan - cold or hot - and mode.

There are 5 different colored vacuum lines going down the dash. Red, Yellow, Green, Brown, and black. Make sure they are connected at the control **** and down under the dash to the mode actuator. If all connected, check for cracks or leaks.

Remember mine was a line off under the hood too. Good luck

 

Ram wheels - the lines are visible under the dash by just looking down by the accelerator pedal. You'll see the colors I mentioned and silver looking actuators.