Gauge issues

[TxGoats]

Ok, I've tried to research this and I have several issues that I think could be a grounding problem on my 71 c10.
When I fill up, my fuel gauge goes past full to about 2:00. My temp gauge stays on cold. I unhooked the connection on the block and grounded it and it just jumps about 1/2", not all the way to hot. My oil pressure gauge shows all the way to the right and the volt meter hasn't ever moved.
I replaced the dash bezel about 3 years ago and that's when this all started. Can someone point me in the right direction?

[VetteVet]

Originally Posted by TxGoats

Ok, I've tried to research this and I have several issues that I think could be a grounding problem on my 71 c10.
When I fill up, my fuel gauge goes past full to about 2:00. My temp gauge stays on cold. I unhooked the connection on the block and grounded it and it just jumps about 1/2", not all the way to hot. My oil pressure gauge shows all the way to the right and the volt meter hasn't ever moved.
I replaced the dash bezel about 3 years ago and that's when this all started. Can someone point me in the right direction?

Try running a ground wire from the gauge cluster to the cab at a good grounding point. Looking at the back of the gauge cluster you will see several small screws that would make nice connections to ground the wire. Notice the small wire in the top left in this picture on a cluster screw.



Your oil pressure may be mechanical with a small metal or nylon tube going to the back of the gauge. This tube runs to a port in the engine block just behind the distributor and oil under pressure runs in the tube to the gauge to move the needle. If you have an electrical oil pressure gauge then the sender or the wiring to the gauge may be suspect.

Are you talking about the battery gauge or an aftermarket voltmeter? The wiring is different between the two. I suspect you mean the battery gauge which has two small fuses one in each wire, that are located in the engine compartment by the right fender junction bolt by the battery and one by the left radiator core support near the horn and voltage regulator.

[TxGoats]

Yes Vettevet, it is the factory temp and oil gauge. I will check those things today. Another question on the fuel sending unit. It has the tan wire plugged in but the tab that is on the sending unit doesn't have anything on it, shouldn't there be a ground wire there too, and if so where should it be grounded too?
Thanks for your help