Valve, Fuel system selector

[RickB]

Hi

I have recently purchased my first ex military 6x6 GMV. 

It has a problem with its fuel system in that it will only draw fuel from the left tank.  I have checked and cleaned the plug going into the valve and it only has power to what i assume is the left side (2 wires)  the other 2 are showing nothing at the valve.  I have also checked the switch in the dash and it is only show 12 + volts in 3 terminals and nothing in the other 3.  fuses are fine.

Can anyone give me some advice as to what is possibly going on.

Rick

[asmit]

If I recall correctly, when I was debugging my fuel changover valve I found that when you toggle the switch in the dash to the other tank it reverses the polarity at the changeover valve.
Here is an excerp attached from the RFSV dual fuel tank supplement, I am assuming it is the same as the 6x6 configuration.
You can find wiring diagrams here: https://www.remlr.com/wiring.html