2005 Grand Cherokee heat only works on max temp
I am having a problem with my 2005 Grand Cherokee (Limited 5.7 Hemi) cabin heater. After the engine is warmed up, the heat will only work at the maximum temperature setting (set on the RED dot of the climate control). As soon as I move the dial up one notch it gets cold. This happens on both the manual air temp setting and the auto setting. The blower works perfectly. Any ideas what is causing this? I'm at a loss and frustrated... Thanks in advance for the help!