I have a 96, 150 that I put a long block 5.0 in 3 years ago. Family issues have set me back and I am just now getting it up and running. It starts right up and sounds good but the oil pressure gauge is reading "negative" on the dash. By which I mean that when I turn the key on, the needle moves into the middle of normal range but when you start the truck, the needle moves beyond low. I have had no over heating.
I made sure to prime the oil pump before I started it a month ago, have no leaks anywhere, and have put around 20 miles on the truck with no problems. Now I did have to put a wire harness from a pick and pull on when we first started the project, but was unsure if me crossing wires would cause it to read backwards.
So I guess my question is, what would be my best course of action? is there a way to check if the oil is circulating properly without like pulling valve covers etc.?

 

There should be only one hot wire running to the transducer/oil psi sending unit. If you want to check pressure just plumb an analog guage where the transducer is.


Hope this helps

 

Sending unit is located driver side, between oil filter and front of block correct? Will give it a shot and post results. Thank you.

 

Just so you know the stock gauge is a dummy gauge. Basically it reads 5psi or none. If you want to know exact pressure run an electrical gauge in the cab. On a cold start with 0W30 I read about 75-80 PSI on a stock style pump. And about 25-30 when hot. 5.0 engine btw