where are failure points in the 12 volt power supplied to the auxilary air valve? i got no voltage on the wire that feeds the aux. air valve heater.

thanks

Thats on the same circuit as the fuel pump. If the pump runs, the aar should have power. Check the plug at the relay board

Aside from the shared relay, it also shares a fuse on that same board (On the 2.0). Can't recall which fuse it is Haynes has the diagram for it.

Rear fuse.

also shares power with the heater blower fan.

And the rear window defroster, if you have one.
Where did you check that you see that the AAR has no power? There is a plug near the AAR and I suspect there is where, but you need to check also at pin 12 of the 12 pin connector on the relay board.
Tom