After driving for 3 months with a dead temp gauge, I finally dived into the compensating board.
Yes, I first checked the other stuffthermostat, voltage regulator, sensor, wiring, connections, and even the gauge. All were OK.
I replaced the LM2902 quad op amp and the PNP transistor on the comp board, and temp gauge back to normal! I don't know which of the two was at fault, but since I have a supply of each part, I didn't care to spend the effort debugging to the actual part. In goes the new, out goes the old.
|