my oil pressure gauge bounces around erraticly at times and some times it completely pegs out for a second. I put a V8 into my blazer so it's a real pain in the *** to change. my question is.... Since the oil pressure switch powers the vehicles fuel pump after it's started ( from what I understand I could be wrong) by me simply unplugging the fuel relay while the truck is running and if the oil pressure switch is good my blazer should stay running correct? And if the oil pressure switch is bad the vehicle should die when pulling the relay? Can anyone confirm this? This test does work with my 1998 k1500.... Pull relay and it stays running. But when I pull my blazers fuel pump relay it dies. Any input? Or could someone pull their fuel pump relay out with their blazer running and tell me if it dies or stays running? Would be greatly appreciated.