94 F250 IDI Turbo I put a new starter solenoid on I got in turned the key to the WTS an herd a huming sound coming from the GP controller I had a good one so I put it on Now my GPs aren't gettint hot enough I tested the control unit with a ohmmeter,checked wiring harness an the relay has 12.90 volts with the key off All the GPs are good