77 k3500 fuel gauge wire ?

[4x4k30]

I cant find the fuel gauge wire from the dual tanks up to the fuse box the wiring diagrams in the 77 ck truck manuals show it nowhere either I would like to see a pic of it if any body can show me the wire itself and where it goes .needs to be a 77 model with dual tanks

[72k20Farmtruck]

I just rewired mine, also a 77. It’ll blow your mind lol, GM decided to run the wire out from the switch, out the firewall, down the frame with the sending unit wires, cross the frame at the crossmember where your switching valve is mounted, and in the vicinity of the switching valve is a fusible link/connector on your gauge wire, where is continues back up the frame now on the passenger side, crossing the the top of the motor in the main loom and ends up going into the fuseblock. Have fun tracing it out, i upgraded mine to the newer style switching valve with the 6 prong connector where the sending unit signal is switched at the valve instead of at the switch.

[hatzie]

this is my writeup on the dual tank electrical.
http://67-72chevytrucks.com/vboard/s....php?p=8173538

There's a molded disconnect on the RH frame rail near the valve. It looks like the tank connection for the senders. The dual tank harness has a pin just like your sender and the gauge wire has a socket just like the wire you plug onto the sender.

[4x4k30]

ok I forgot to add my 77 has a ls 6.0 both tanks are the newer 87 fuel injection tanks with new senders and in tank a/c delco pumps . the orginail dual tank dash switch is the orginail 5 prong switch.. when I swaped the tanks I also swapped the fuel tank selctor valve the p/o has just installed a single wire 3 prong switching valve just running on the right tank .I took it off and I now have the 6 prong Pollack switching valve and I am just running on the right side tank . when I replaced the old tanks I got rid of all the wiring at the tanks except for the 5 wires running to the new 6prong Pollack valve that run back to the in orginail dash tank switch. also I replaced the cluster with a tach cluster and a tilt colum from a 79 k20 other than that that's it .so im am missing the wiring that goes from the new senders up to the fuel gauge in the cluster .