went wheeling last weekend and about halkway through the check engine light came on and the temp gauge started going crazy first it would show normal 210, then sweep over to the red pause then back to 210 then to 100 and back and fourth sweeping half the gauge each time pauseing sometimes.
the jeeps not running hot and i tried replacing the sensor. Didn't change a thing. i read the code and its coming up temp sensor low input i'll get the code number in a few. i've run into short to ground issues where the gauge stays pegged in the red but never had one just randomly jump from cold to hot to normal and all around.
Any ideas are appreciated
mike

Sounds like you have worn insulation and the wire is grounding to short intermittantly.

Time to trace the wire and find where it's rubbing.