Oil Pressure gauge pegs when headlight turn on?

[nbluesky]

When I was driving my RV today I noticed if I turned the headlights on the oil pressure gauge pegged to full on. Also the illumination does not work. Has anyone seen this before and knows what to check?

94 HR Navigator on Spartan chassis.

[Skip426]

Sounds exactly like the gauge and dash lights are fighting for a wiring ground.

You'd have to remove the gauge panel and follow the wiring to find the dash harness ground stud ; and clean or repair as required.

[USMCRET]

Skip, generally speaking, where is that ground normally found? Is it likely to be within reasonable proximity of the gauges?

[nbluesky]

On my Navigator the ground all go to a post underneath/inside the front access area above the generator. I will pull that cluster of gauges and start checking. Thanks!