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.

 

I don't have any wiring diagrams for ya, but it really sounds like a sunk float. Is there a body on the chassis now? If not, you could probably just pull the fuel sender without pulling the tank.
What engine and fuel system does this have?

 

It's a motorhome with a 460 carburated.

I finaly found the right diagram and made some reading on the sender, and, I think the problem is in the tank.

I'll try to drop it later.