1988 Dodge pickup, why do I do this stuff? Anyway got it two years ago it’s been a ‘work’ in progress to say the least. After replacing the fuel pump again got it running nice but no oil pressure (I knew this before) so I had a Ramcharger back 20 years ago the had no pressure found out it had baked sludge in the pickup after pulling pan. I thought this was same issue so off came the pan, no sludge but someone had been in there at some time before I got the truck. Changed oil pump and screen and checked bearings (new) still couldn’t figure why no pressure, maybe the pump? Anyway back together (a choir laying on the ground!) changed filter replaced oil, fired up still no pressure, light stays on. So on a whim I put a hard oil line and gauge, 65 pounds of pressure, the dang sender unit was the problem the whole time !!!! Funny how you get on one tract and can’t see the forest for the trees!. Anyway rant over just had to get it off my chest.