After getting into a bit too much mud, I was over heating. I cleaned out the radiator, replaced the radiator fan, and cleaned the engine. Now after driving for a while if the ac is on, the jeep will still heat to the third line on the temp gauge, before now it has always ridden just to the left of center. Turning the AC off and turning on the heat will immediately return the temp to center. Any ideas what to check for?

 

The usual stuff. It's either air flow OR coolant flow. Since it seems like you did the air flow stuff (providing everything is operating correctly,. ie fan speed, unobstructed grill, radiator fins etc) Next is antifreeze condition, thermostat operation, water pump operation, serpentine belt age slipping. Replace antifreeze, thermostat and serpentine belt to be sure. Good luck. Let us know what you found when fixed. OH btw maybe the temperature gauge is flaky. Read the actual temperature with a thermometer or infrared thermometer. They are under $30 in a few places. Harbor Freight

 

I got back in looking at it, the radiator still looked a bit dirty, I drained the coolant and pulled the radiator out, the lower thirst of it was still totally clogged with dried on mud, had to soak it for a while to get it to wash out. All seems good now.