I installed a J-spec motor in my 87 TII and noticed the oil pressure was maxed out. Looked at the sending unit and it was crushed. So I put the old sending unit on and now it reads no pressure. So I bought a new one and it still reads 0 oil pressure. I hooked up a mechanical gauge and it has great oil pressure. So the crushed sending unit must have broke the gauge by maxing it out. Any way to fix, or replace gauge?
Thanks

 

Is the gauge "maxed" out even when the sender is disconnected?

 

No, it was originally maxed out with the slightly crushed sending unit that came on the J Spec motor. I took it off and put both the original, and a new sending unit on and now it reads nothing, zero pressure. But it has great pressure on a mechanical gauge. So there is oil pressure and the gauge worked before the install. So I am guessing maxing it out for about 20-30 minutes of drive time hurt the gauge.? I know you can ground a gauge wire to check gauge and if it maxes out the gauge works, do not know why this would hurt it.

 

Get a 200 ohm resistor from Radio Shack for about .69 cents, and attach it temporarily on the senders wire, then put the other end of the resistor to ground. You should read about 30psi on the gauge when this is done. Also just out of curiosity , put a voltmeter on the senders wire and see if you have 12v there. I do the 12v check before buying the .69cent resistor. No voltage means the resistor trick ain't gonna work.