I had some random erratic needle movement on the oil pressure gauge in the 86 GT. I have a spare gauge set so I wanted to swap it into the 86 and see if it was repeatable in order to begin isolating the problem. I removed the old gauge set and installed the other set into the assembly. When I tried to connect the connector it wouldn't go.
I was surprised to find that the connector on the original gauge is on one side of the circuit board and on the opposite side on the other. (see pics) The connectors appear identical except for this odd orientation. The connector even fits if I turn the gauges to face the windshield. Unfortunately the wire harness isn't long enough, nor is there enough slack, to turn it back to face the right way and still allow the gauge pod to seat correctly. The connector from the 86 is mounted on the component side of the board. The other one (year/model unknown) is mounted on the opposite side but seems more correct since it seems to fit into the cut-out provided.
So are the gauges different between models and/or years? Are they the same electrically? I might connect it up and rig it in place upside down just to try to confirm or eliminate the erratic needle.
gauge from the 86
side by side