Quote: 92 Ram used an SBEC controller. ECT is on a dual range scale. At cold start it has a 4.75 - 1.25 volt range. At approx 125 degrees F, the ECT volts should have dropped to 1.25v. At this voltage the SBEC internally adds a resistor and the ECT volts JUMP UP to approx. 3.75 and then again use the 5v scale downward as the engines continues to heat up. Verify that this transition is happening at approx 125 degrees then MOVE on............
Good luck
I have a 92 5.2 Dakota that had the same symptoms. Had to replace the black box on the fender under the hood. SBEC controller?? Anyway. after we replaced it I never had another problem
