I tried searching, but couldn't find a solution. my factory coolant temp gauge only moves up to the "normal" range & the fan only comes on when the gauge moves up, but this only happens @ idle. if i let it sit & idle itself up to temp, then put it in gear the gauge drops down to the second line from the bottom. also, if i just start it & go, the gauge never goes beyond the second line from the bottom, and the fan never comes on. the fan does come on if i connect my code scanner & check for koer codes. the radiator, thermostat, water pump, & coolant temperature sending unit beneath intake have all been replaced in the past year. the a4ld was rebuilt about a year ago as well, if this helps any.