One of my gas tanks is reading incorrectly

[99-LS1-SS]

I've got a 1984 K10 with a 305 and dual gas tanks. When I am switched to the right hand tank the gauge reads correctly. When I'm on the left hand tank the gauge reads way past the full mark(approximately at the 3:00 if you were to look at the gauge like a clock). It has recently started doing this. Has this happened to anyone else? Where is a good place to start for fixing it?

Thanks.

[Jonboy]

The tanks are grounded separately. I would check the ground on the suspect tank.

[99-LS1-SS]

Thanks. Any idea where the ground on the driver's side tank terminates?

[Jonboy]

One end is attached to the tank near the sending unit, and the other end of the ground should be bolted to the frame somewhere near that (6 or so inches away).

[99-LS1-SS]

Thanks again Jonboy. I'll check it out tonight.

[motornut]

check the sender wire while your there
i've found the sender off or open makes the needle go to 3
ground it and it should read empty

[99-LS1-SS]

I got to look under the truck this morning and the wires running to the left hand tank were laying on the driveshaft. It wore through the ground wire. I have some 20 gauge wire, can I use that to bridge the gap between the two wire pieces?
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[Jonboy]

That would have to be better than what you have, but if you could source something lager it would be better. You can ground it anywhere, so just splicing a piece of wire with a ring terminal would work, and put that somewhere on the frame.

[hatzie]

There should only be one wire running to the LH tank from the valve. It's the sender wire and it's 18awg. Splice in the same gauge wire and wire tie it to the frame crosspeice.

The stock ground wires are very short even on the 87-91 RV TBI squares. Just enough to reach from the sender lock-ring to the frame.

[99-LS1-SS]

Originally Posted by hatzie

There should only be one wire running to the LH tank from the valve. It's the sender wire and it's 18awg. Splice in the same gauge wire and wire tie it to the frame crosspeice.

The stock ground wires are very short even on the 87-91 RV TBI squares. Just enough to reach from the sender lock-ring to the frame.

Thanks for the specific information. I was able to get some 18AWG and it works again.