My 99 xj is only blowing cold air when the heater is on full blast. The A/C works fine. I have pulled off all the hose's and made sure there clean and even tried to blow out the system. Any other help would, HELP. When i did blow it out the antifreeze what brown with chunks in it. The jeep doesn't over heat, infact it run's like a champ. I've had it for 2 years and no overheating issues what so ever. If you can help please do so...

Thanks

 

please lots of answers.

 

Quick way to check if the heater core is plugged... Feel the hoses going into the heater core with the engine running. if one is hot and the other is cold then the heater core is plugged and should be changed out. Since when you blew out the heater core, brown chunky stuff came out. This could be what is causing your lack of heat.

 

in the 99 i believe the heater core is under the dash. Any tips for getting it out?

 

put a garden hose to the fittings and flush out heatercor if anti freeze and brown chunks came out its most likely not plugged reasemble all hoses and see if heater control valve is moving when you change to heat on dash

 

it will look similar to this if not moving check for vacuum at small hose if theres vacuum try and move lever carefully