I know I've got some electrical issues, but am having a hard time tracking the cause down.
I checked and cleaned the main grounds to the body and the engine, so I'm assuming the gauges have a good ground.
Anyone know what could cause this?

 

the wire is off the sender.
OR the wires to the gauge are shorting out.

 

^Like he said. Check the wire connections by the thermostat housing ( where top radiator hose connects to the engine) if everything is good there, you will have to trace the wire all the way back to the gauge cluster. Maybe take the gauge cluster out and check back side.

 

The unit by the thermostat is the thermosender for the ECU and has nothing to do with the gauge.
The gauge sensor is below the oil filter housing, next to the oil pressure sending unit.

 

Haha, whatever dude... :p

 

Gotcha