Oil Gauge Problem

[Eyegore]

OK the old oil gauge was not working not even moving when power was applied. I replaced it with another gauge and it powers up fine, but when I start the motor it pegs clear over to the right side, to the highest psi then it stays there when I turn the motor off, to the right side that is. After that I click the ignition back on to power, not cranking the motor, it then goes back to the left side of the gauge to the lowest psi while power is kept on. Can anyone give me a hint of what might be the problem and a solution? Is it the sending unit that is the problem? A while back at the autoparts store they showed me a completely different sending unit that is in there now, it was a canister type.
This is for a 1978 454 3/4 ton.

[old Rusty C10]

sounds like a sending unit ... i always use the guages which arent electrical tho

[salrod00]

oil sending unit. you might want to take yours off first and take it up there with you. there are different psi ratings on those..oh yeah my ran around 8 bucks.. good luck.

[Prong]

Originally Posted by salrod00

oil sending unit. you might want to take yours off first and take it up there with you. there are different psi ratings on those..oh yeah my ran around 8 bucks.. good luck.

My 79 did this--turned out to be the ground wire. Check out the ground leads that run from the loom to the 6 prong post on the cab wall (above and left of the fuse box).