a/c mode door issue??

[Mrgoodwrnch]

05 F-250 just wondering if anyone has ever had a problem with their a/c mode door, it seems like it takes alot longer than it should before it actually swithces from def and floor to vent, just on start up, i know older vehicles all that is operated by vacuum but i wasnt for sure with my new truck, aby help?!?!?!?!

[dhanna6powerstroke]

Originally Posted by Mrgoodwrnch

05 F-250 just wondering if anyone has ever had a problem with their a/c mode door, it seems like it takes alot longer than it should before it actually swithces from def and floor to vent, just on start up, i know older vehicles all that is operated by vacuum but i wasnt for sure with my new truck, aby help?!?!?!?!

My truck did that for a while. Realized I knocked the grey vacuum line loose from the valve that is inline with the heater hose on the passenger side of engine. Reconnected the tube and no more problem.

[Term3]

Yes it is most likely a vacuum leak. The vacuum pump is on top of the right side wheel well just behind the vacuum tank so if it keeps on running then you have a leak somewhere. Most common leak area are the vacuum lines to your 4X4 front axle.

[winghoov]

plug the outlet for your hubs at the valve, check you heater controls. If they work you have a leak in hub system.