taking all bets.. but my money is on the gauge itself.. i ran every diagnostic in the book. including on the wiring of the temp sensor.
and my research brought me to someone on here saying that the temp gauge. once pegged out from an overheat. must be replaced. as it will always peg out once the car is started.
does it seem to just FLY up to the H? like faster than a legend can warm up? from a cold start?
its a CHEAP fix. mine cost me 14 dollars for a type two gauge cluster at the junk yard. so not only did i fix the gauge. i now have type two gauges in my 92 ls cluster.. threw some LEDs in while i had it apart too.
it was a win win.