Bouncing/unresponsive oil pressure gauge
 

Hey all, I've got my engine out of the car and want to fix an issue I had last fall and never got a chance to fix. I have a real oem OPG and sensor from a 94 in my car.

My oil pressure gauge is having an issue where it would sit at 0psi, even when the engine was running. Occasionally when the engine got hot it would come to life and work fine until the next time I started it from cold, it could just do nothing. Later on I noticed it doing the same thing but instead of reading a correct pressure, it would flick from 0 to 45psi or w/e the current pressure was, show that for a little bit and go off, come back, go off, etc. I already checked the wiring to see if it was loose, but found no such luck.

I was hoping this was a ground issue but really I'm only have one other issue; When I turn on the left blinker occasionally the driver's headlight would dim coinciding with the flashing turn signal. Sometimes it's a bit of a dim, sometimes it's almost completely off. I'm unsure what could cause these two issues, anyone have any suggestions?