For the past year or so my temp gauge seems to be dancing. It jumps up and down from zero to about operating temp and when i drive jus drops back to zero. Lately it wont even move just stay at 0. I have changed the water pump and changed the thermostat followed with a coolant flush about a month ago and nothing really changed. Coolant also leaks out my radiator cap after driving but thinking maybe its jus a bad radiator cap cause it was cheap. Is it possible the gauge? or the thermostat housing sensor? or a bigger issues? not sure jeep feels to run pretty good tho

 

check the temp sensor

 

The temp gauge is powered by a temp sensor on the back of the motor.


Check it for a loose connection or bad wire. May need a new sensor. The sensor on the thermostat housing powers to and from the PCM, not the guage.

 

96 is a bastard year...you might have that sensor shown above...or it might be driven off the tstat sensor in late model 96. Sometimes that back sensor is tough to see. Easiest way to know is get engine warm or hot....disconnect sensor in thermostat housing. Start jeep....if temps remain warm or hot then aux sensor at back of block...if goes cold then runs off sensor in tstat