Been a while since I had my 88 GT on the road (needed a clutch). Anyway, it amazes me how these electrical gremlins pop up when a car sits. I put a clutch in, cleaned up the engine compartment & she now runs & goes forward & backward. But, heres the problem the oil pressure guage is pinned when the engine is running or the key is on. Key off it's far left at zero. I took the sending unit wire off & it does the same thing, no change. Shouldn't it not move at all when the wire is off ? Sending unit plug center pin to ground does not cause the needle to move, stays far right. Key off, needle drops to zero. Now, here's the really weird thing. When I hit the trunk release button, the oil pressure guage jumps up half way. If I hold the button down the needle stays at halfway. The brake warning light on the dash comes on when push the trunk release also. The trunk release relay is clicking. The trunk lid isn't on but when pushing the button there is 12 volts to one of the terminals in the engine compartment plug. No voltage at all to this 4 prong plug without the release button pushed. Obviously, something is miswired but I've looked at all the wiring info I could find & still don't have a clue. Anyone point me in the right direction ? Thanks
Edit... after digging around in the archives, I found that Ogre addressed a similar post long ago & the brake warning light & the oil guage jump is due to a phantom ground across the guages. I'm not the only one to see this. But my oil guage is stilled pegged far left key on or running. Grounding center post (12 volt) doesn't budge it. Key off it goes back to zero.
[This message has been edited by red88gt (edited 01-13-2019).]
