Strange Heating Issue with my 02 KJ

[drdanks]

When turning temp dial to hot.. blows hot air for 5-10 seconds then goes cold. When turning temp dial to cold... blows hot air for 5-10 seconds then goes cold.

Replaced 2 blend door actuators and resistor. Flushed coolant system including heater core. Flushed heater core again. Heater core hoses are both hot. Doesn't seem to be a coolant issue.

Fan at all levels work. Very good air flow from all areas when you turn the dials. Seems like it is only the hot/cold dial

About 90k miles

Could this be something deep in the dash (another blend door) or possibly the climate control panel?

 

[ltd02]

I responded on the other forum yesterday. You replaced two blend door actuators or replaced the blend door actuator twice? There is only one blend door actuator.

This is what I did: http://www.jeepkj.com/forum/f202/how-replace-hvac-blend-door-actuator-59206/

 

[drdanks]

Thanks for all your info! I was able to bleed the coolant system to get any air out. Gradually the air was warm and consistent. Eventually it was hot and consistent. The cold side works too. When done I recalibrated the blend door and all seems to be good.

 

[ltd02]

Air in the system after a DIY flush seems to be common cause of heating headaches. I'd wait until the dealer is running a flush special. Chances are good they'll have the equipment to do it easily and without the air in system problems.