problem:

my car runs on LPG. therefore, the fuel pump is most of the time working for nothing. it just spins the gas in the tank without any use of it.
plan is to cut out power supply to the pump when car runs on LPG.

I can't do it on fuse panel in engine bay, becouse removing the fuse cuts power to the pump but also cuts ignition.
I have to find a single wire that runs power to the fuel pump and I can't find it on the fuse panel inside the car.
I know it's probbably fat and red(ish) but I don't have scheme for the wirings and wouldn't like to melt something accidentally.

so the question is:
-what colour is that wire?
-can I find it on the panel inside the car?

voyager LX 1997, 2,4 liter gasoline