front tank empty. can't see a low fuel light. with the switch in the down position, the fuel doesn't feed to the main tank.went to the RM web site and found the HT 15000 installations, BUT there isn't a aux tank wiring diagram. what i want to do is usually run off of the aux tank, then when the fuel is low then switch to the main tank. ( on long trips) how do i seperate the stock wiring to get this done? i think this 3 wire connector goes to the selector switch