1999 1500 ram (2w) 125,000mi.
Got the truck it was dead, placed a new battery.
Truck powered up, the only thing is the a/c system.
STUCK IN DEFROST MODE

With the dash controler disconnected (vacuum type) and the engine running I thought i would find vacuum on one of the hoses at the connector under the dash.
I did not find vacuum.
Went to port on side of motor, removed the hose that goes thru the fire wall.
Pulled the one way valve off from the end of the hose that would be connected to the motor and found vacuum.

I would think that the hose off the motor port thru the one way valve and thur the fire wall to the connector under the dash and then upto the controller at the dash is a straight tube ?????

So what could it be (crushed hose) clogged hose .
Thanks for any help

 

https://dodgeforum.com/forum/2nd-gen...ild-vents.html

 

I Read the thread.
I have the tube open at the fire wall and under the dash.
I can still find a vacuum at the firewall end of the tube.
Haven't tried it the other way yet.
Straight tube from firewall to under the dash ?no? ...
Thanks.

 

Remove the cowl, I think there is a canister under it. And does your cruise control work ?

 

After replaceing the front rotors and pads.
I now think this truck is a 1st gen.
Still have the defrost mode fault.
Will shearch the past htreads there.
I am sure I am not the 1st with this fault.
Thanks for the help

BBGUNDAVE.