M38 Gauges question

[TR BUCK]

I am in the final stages of completing a rebuild of a 1952 M38. The problem I am having is with the gauges, the temp, oil pressure and fuel gauges, when I turn the main switch ON, the indicators on the gauges peg themselves to the right. What did I do wrong??

Tom

[Jeeps4Brains]

The circuit for the gauges, the power has to run to the gauge and then out to the sensor / sender. The sensor / sender then offers resistance to the power and passes it back to ground / earth through the body. So the dash gauge is like a balance beam measuring the difference between the power sent and leaking out of the sensor / sender ground.

If the sensor / sender is bad or not grounding properly then the power goes into a dead end and can not leak to the ground. Also the gauge has to be grounded to the body. If you really painted the dash well and the gauge panel it might not be grounded. It's time to take a meter and see where the breaks in the circuits are.

[TR BUCK]

Thanks for the reply, Checking grounds will be the first thing. Before I had the gauges mounted in the dash, I had the temp gauge rigged to run off the sensor and worked fine. So tracking the missing ground is what I will do.

TRB

[TR BUCK]

Final results: Fuel sender grounding repaired, Oil Pressure sender was bad, replaced; Temp sensor bad, replaced. all is well now.

TRB