2004 Grand Cherokee Overland with Intermittent heat problem

[floyd5194]

Hey everyone, I have a 2004 Grand Cherokee Overland with the dual climate control. The problem is that the heater will all of a sudden start to blow cold air. It starts out working perfect, i mean you could roast a hot dog in there but at any given time it will go cold. My first thought was the blend door issue but both sides go cold at the same time but if you turn the temp control to high it works but you have to leave it on high because if you lower it off high it goes cold again. The reason i dont think its the blend doors is because it has dual climate and both sides go cold at the same time. I am leaning towards the control unit but dont really want to spend a lot of money on something that is not the problem. Any help would be appreciated. Thanks
:givemebeer:

 

[SteelHeadz]

Either way this goes, there should be a Dtc active or stored in the HVAC module. The dtcs will help determine the root cause of the issue.

 

[tow_hook]

ya when the blend doors go you will know esp if it's winter.. the vent door might have broken, mine broke too 3 days before x-mas last year no heat at all.... errrrr if ya bring the 3 to the run poss 3 times it will flash a code for ya.... hope this helps...