So I have an 07 and i lost heat on the driver side at first, now its gotten worse to where the pass side is barely working and driver is ice cold. My co worker said he had the same issue on his and the plastic box that the heater core goes in deteriorated and its very common and a huge pain to replace.(and he said thats my issue) He said it just allows outside air to dump into the vents. In all my research, everything just points to the core itself. Its not leaking but im sure the core is plugged. the jeep was abandoned for about 4 years before I rescued it and got it running, has about 130k. any insight to that matter? im fine cutting the dash support thing to splice one in

another odd thing is the vent selector doesnt want to click fully onto defrost, like when i move the knob there it springs back to the next spot which I think is floor+defrost. sometimes it will stay there but then I have the same issue in the other direction where it doesnt want to move to dash. I figured the system was electronic and not cables but its acting like a cable system that doesnt want to move all the way. anyone have insight on that?

 

Yeah, it's your heater core. The 'Splice in a new core" strategy works well. The most difficult part is getting the 5/8" heater hose sections far enough onto the aluminum tubes. Take your time, it's worth it. I also had the same issue with the mode selector cable. Same symptoms as you. My cable finally broke. You can find new cables online for less than $20.
Best of luck,
SpartanToJo

 

So it is a cable controlled system and not electronic on the old interior? I thought it felt like a cable but figured it was all electric stuff. Good to know, thanks