Trouble in dash A/C paradise...

[JSargent]

I cannot get the white vaccuum control tube to retract selector arm under the dash to max air output, any ideas?? I'm about ready to try an old fashioned choke cable... Help, please! Thanks

1987 345 Classic Motorhome

[bobmiller1]

Best to check all colored vacuum lines with a manual vacuum pump for proper operation....you can do this with the engine off, key on, with fan on so you can tell what is working and then determine where your problem is. On yours vacuum operates actuator for plenum door to open and close.

[JSargent]

Thanks for the info, bobmiller1, and the quick response! Will try this out ASAP.