Fuel gauge not working.

[D.Brown]

I have a 1985 k10 that had the dual tanks but someone took the p.s side tank out. How do i go about fixing the fuel gauge?

[swissarmychainsaw]

There is a factory switch near the ashtray? If it's factory, the switch will change for each tank .

Did you check the fuse? Has it ever worked or is this a new to you project?

[D.Brown]

Yeah this a new project. I forgot all about there being a switch for a tank, first truck that suppose to have dual tanks. The switch is missing though.

[D.Brown]

I found what was left of the switch behind where it was supposed to be. The face plate is missing to it.

[D.Brown]

Still don't know why the fuel gauge doesn't work though.

[Oregoon]

Mine's all over the place, too. I think it's a grounding issue, since it works properly at times. I have a single tank though.

I'll use a dipstick and the odometer until I figure it out.

[hatzie]

1981-1991 dual tanks have the fuel sender wires routed through a switch inside the tank valve. The only function of the dash switch in 1985 is to run the valve shuttle motor left or right. If the valve is missing and the wiring is butchered you'll have to splice the fuel gauge wire to the LH tank sender wire.

If the wiring is still down there and reasonably complete... but not the valve. Or the valve is not properly switching the gauge. And. You have no intention to refit/repair the missing tank and missing/damaged valve immediately you can fit a single wire jumper plug to make up for the missing/damaged tank valve. That way you can fit the missing tank and valve later, when you want it, without kicking yourself for chopping up a perfectly good cab-to-valve harness.

You'll need the following Delphi Packard parts;
1, Weatherpack Shroud 6 Contact Body Delphi Part # 12010975
2, Weatherpack Terminal 16-14AWG Male Delphi Part # 12124582
2, Weatherpack Cable Seal Green Delphi Part # 15324982
4, Weatherpack Cavity Plugs Delphi Part # 12010300
8" of SXL jacketed 16AWG wire

Wipe some Sil Glyde on the cavity seals and the cable seals.
Make up the short wire shunt...

1. Push the wire into the seals with the narrow ends facing the cut ends of the wire and the fat ends toward the center then push them back 2-3".
2. Strip around 3/16" of the wire jacket and pull the seals back down toward the end so the narrow ends come up even with the cut end of the jacket.
3. Put the terminal in your Weatherpack crimp tool and push the wire in till the shoulder on the seal hits the strain relief ears on the terminal making sure that all the wire strands will be crimped inside the terminal.

The connector cavities are lettered A-F
Insert the Weatherpack wire loop you just made into C (LH Sender) and B (Fuel Gauge) till you hear a click in each socket.
Then put the four cavity plugs in A, & D-F to keep crud salt etc out of the other terminals.
Flip the strain relief cover over and snap it down on the tail of the new connector you just made.
Plugging this new connector in will route C LH tank sender to B the fuel gauge wire just as if the valve were present and working.

This is the detail at the valve...