Hey everyone im having issues with my 83 2.8 ranger. When i turn the key on with eng off the oil gauge goes 75 percent up but when i start the truck it will slowly go back down. I put a new oil sending unit but no change. I knkw it cant be all that hard to fix but im not that big on electrical any help is grearly appreciated

 

Welcome to the foum

Oil pressure gauge, like the Temp gauge, is GROUNDED by the sender on the engine, the senders are variable resistors like a volume control or light dimmer, so the gauge is showing how much resistance to Ground thru that sender
The engine is the GROUND, so never use "tape" on the threads of these senders, or if you do, leave lower threads BARE METAL, so sender has a good ground connection to engine

To test if problem is sender or wire and gauge, disconnect wire from sender
Ground that wire using "jumper wire" to battery Negative or engine bare metal
Turn on the key/engine off
Gauge should go to the top and stay there
If it goes up and then comes down the problem is in the dash cluster, so you will need to pull it out, and then you can test the wire and gauge separately

 

Thank man i appreciate it icwill try this as soon as i get off work