84 ram 250 wat wire is fuel gauge

hi i like to know what wire in the wiring harness that goes over the driver side roof to the back is for the fuel gauge i last year re rivoted the camper van and drilled holes in the wires i had repaired all of them but still dont get a fuel guage wire so i wannna re run a new wire any ideas how to trace it for me

It's an 18 gauge light blue wire.

ok thanks can u tell me if its the wire that then goes from the back of the van on drivers side to the passenger side? as this is converted campervan and i dont wanna take all the wood working off

and they never caucked the cab on then rivioted so now i just pealing the rust off damn ppl are cheap

I'm not positive if it crosses over or not, but it appears from the wiring diagram that the fuel sender wire is in the same harness as the tail/backup lights; if that helps any.

somewhat i just wanted to know where i could just by pass the wire near the back jsut wasnt sure if front wire was bad or not but ill try that tommorow as too dark now

ok i traced it but not sure if the fuel pump float is working or not
but is the power from the wire from the gauge suposed be 0 to 6 volts flashing? or is it suposed to be constant 12 volts i know if i short the wire to the ground that the gauge is working but i not sure if the tank one is working or if its just cuz not enough voltage? any ideas or someone can measure the voltage on the line