I have a 86 E350 cutaway with dual tank and the front gage is reading Empty regardless of the fuel level in the tank.

I'm looking to troubleshoot the problem but the wiring colors in the Haynes are not the same as on the truck.

I found another diagram and the colors aren't the same too.

I would like to test my wiring before dropping the tank and can't find the right colors to test the fuel sender.

The wiring from the front tank has a green, brown and couple of black wires.
Also the fuel selenoid valve has 5 wires (red, green, green, brown, orange)
I can't find these colors on any diagrams.

Thanks for your help.