oil pressure gauge or oil pump going?
 

Hey guys, wondering if anybody can help me out, I have a 05 5.4L 3v rolling up on 230,000 km and my oil pressure gauge is all over the place, sometimes its normal, other times its either just below minimum or all-out pinned. I was running 4x jl 10w7's off stock wiring before I got a battery isolator and a second battery, and it caused me all kinds of electrical problems due to pulsing, is this a remnant of that?

Check engine light has never come on, the engine never cuts out, sounds/runs healthy as ever, though I keep up with all my maint pretty well.

Going to be driving long distances quite a bit this summer, so hoping to head off as much as I can.

I would replace the sender. Usually $20 or less. Located behind the oil filter.

thanks, will give it a shot