Rear Air troubles

[Smasal]

Not working at all. Front controls on the overhead console are lit up but dial doesnt do anything. the rear controls as well dont do anything. is there a second motor i need to check or relay or something? the home link and lamp lights work fine so I know i have power in the front.

 

[Blackonwhite]

I'm having this same issue

 

[SunlitComet]

wrong year forum but yes those controls are for the auxiliary system in the rear corner of cab. disconnect the fan and run voltage tests while changing speeds up front. btw there is a 30 amp fuse in under hood box labelled rrhvac which feeds power ultimately to that blower motor. and there are some relays in between of course.