I have an 02 that I've been having some wiring issues with, and I need to manually check the oil pressure. I was looking in the manual, and it looks like the oil pressure relief valve on top of the oil filter is used to check the oil pressure on these trucks. Is this correct? I just ordered an oil pressure test kit and wanted to know the easiest place to hook it up.

Thanks for help or suggestions.

 

I have run a mechanical oil pressure gauge to the port on top of the oil filter housing, like you describe on several Cummins trucks.
Works great.