Looking to see if anyone has experienced this and if so what is the solution. I have a 08 JKU and my heater only blows hot on the passenger side but still blows air on the driver just not heated. This isn't so much of an issue in SoCal but when I went to Wyoming this became a serious problem in negative temps(this when it happened ) any help or suggestions welcome.

 

If I remember correctly it's a common issue with sand from casting in the core. Do a forum search and you'll find it

 

Another common cause is a broken, or otherwise malfunctioning, blend door.

 

Oh Man...not this again.
Heater core is the sole source for heat. Imaginary sand in the coolant blocking heat from core ends at that point. Get with the program folks. If you have hot air anywhere in cab the core is fine.
Which when one side is warm and not the other it's your air flow blending that is the culprit.
This is getting to be like the movie 'Groundhog Day' google it kids

 

Do the newer Jks have vacuum blend doors?? Cause my 07 is just a crappy ass cable and plastic actuator.