NO OIL PRESURE! HELP!
I have an 87 Wrangler Laredo, 4.2 I6, 5 speed. 165k. I am having a problem with oil pressure. The problem started where I was reading no oil pressure on the guage. It was past 0 in the negitives. Since then I have replaced the sending unit, checked the guage etc. Still, it reads no oil pressure. When I connect the wire that comes out of the sending unit to the positive battery terminal, the guage jumps, so there isn't a problem with the wiring as far as I can tell. (Right?) I've tried grounding the sending unit manually, and the guage still won't move. I hooked up a mechanical guage, and its reading 50lbs of oil pressure - VERY healthy! So what is my problem? There is only supposed to be 1 wire coming out of the sending unit right? Does anyone have wiring diagrams for this...its not even in my service manual! Help. I've been battling this for over 2 weeks now so if anyone has any ideas I would be very happy to hear from them.