It pegs hot side even when temps are around 120 degrees. It moves the gauge as soon as it just starts to warm, waterpump,radiator,therm all new and working. dosn't matter if thermostat is in or out. thanks for all your guys advice,if you have any more i'll take it. Jeffrey

I'm older than my truck but it's smarter than me! 66 GMC 3/4 ton fleetside 283, turbo 400.