The OP says over 100 psi at idle, which is certainly abnormal.
When chasing an
oil pressure issue, a master
oil pressure gauge or at very least, a mechanical
oil pressure gauge needs to be fitted to the engine.
While this is being hooked up, the gauge circuit can be tested.
Generally the sender wire grounded with the key on should read zero on the gauge.
A decade box is a handy tool for testing gauges if you have the sender resistance specs.
Gary