AC only blows out defrost vents

[bstedman]

97 Dakota V6...has no vacuum coming to the back of the AC control..tried to trace it out under the hood and could not find it...any one have directions on where the vacuum connects to the engine?

[tyler005]

Did you resolve your problem? I'm having the same problem. Thanks

[bstedman]

Originally Posted by tyler005

Did you resolve your problem? I'm having the same problem. Thanks

Yes I did...the vacuum line from the firewall to the heater control had a leak. Somehow the line developed a crack.

[tyler005]

Originally Posted by bstedman

Yes I did...the vacuum line from the firewall to the heater control had a leak. Somehow the line developed a crack.

Where is that line located? Thanks

[bstedman]

Originally Posted by tyler005

Where is that line located? Thanks

The line enters the passenger compartment, from the engine side, just to the left of the brake booster. It usually is a very small plastic line if it has not been replaced. On the passenger compartment side it is very hard to trace, especially if you have AC.

I found my leak by removing the vacuum line asm from the back of the heater control switch and putting air pressure thru the black line, which is the main line to the switch. I could then hear air blowing out under the dash. I bypassed the leak by running a rubber hose from under the hood to the back of the vacuum switch.