Elliot 7 #1 Posted January 21, 2020 Hi Guys, I have a 1990 520H with the Onan P220g. It starts and runs great for about 30 minutes then the oil pressure lights will flash and it shuts down, after a few minutes it will go again and do the same thing. I am thinking it could be the pressure switch is clogged or failing or the oil pump is going. Any ideas ? and can anyone tell me where I will find these parts on the engine? Thanks ! Share this post Link to post Share on other sites
gwest_ca-(File Mod) 10,496 #2 Posted January 21, 2020 Does the oil light flash and then shut down or does it shut down and the oil light flashes? The oil pressure switch has no control over the ignition. Controls the hour meter and oil light only. No oil pressure oil light flashes. With oil pressure the oil switch opens the oil light circuit and grounds the hour meter so it will advance. No oil pressure hour meter will not advance. Just in case the ignition switch gets left ON without the engine running. Garry Share this post Link to post Share on other sites
lynnmor 6,777 #3 Posted January 21, 2020 Wiring or switch problem. Share this post Link to post Share on other sites
formariz 11,849 #4 Posted January 21, 2020 That light is certainly a great source of frustration and uncertainty about what the actual problem is. Extremely hard to diagnose problem and labor intensive due to the fact that shroud has to be removed to get at source of problem and then replaced to test it. That is the reason I opted to install an oil pressure gauge and also bring the sensor out of that area so it can easily be checked and serviced. 1 Share this post Link to post Share on other sites
