Have a question, have had my jeep for just over a year now. Ive had the top off multiple times but last week was the first time ever taking the doors off, boy was that a task.

Anyway, I went to my brothers house friday leaving around 8pm. It was a little chilly so decided to turn the heat on the jeep. didnt pay much attention to it at first as the jeep was still cold and hadn't warmed up, but 5 min into the drive i noticed i wasn't getting any heat.

The blower blows nice and strong, i can select the different positions (feet, vent, mix, defrost). I then pulled the glove box and checked the filters, replaced with K&N filters last year when i bought it, they were clean. I then grabbed the 2 aluminum tubes going to the heater core and both are burning hot, could only touch them for a few seconds, so it seems im getting flow throw the heater core. I noticed a module on the passenger side and it seems to be working, as i move the dial for vents i can see it working.

Looking at a few youtube videos it seems there is a module on the driver side that is the blend door. Would i be correct as to assume this has gone bad and needs to be replaced?

Its kinda funny that everything was working till i took the doors off and then boom no heat. i wouldnt think jeep was that silly as to disable the heater if the doors are off.

 

If you have a hot hose going into the heater core and leaving the heater core then it seems like your assumption is correct (hot coolant is flowing through the HC but the air from the blower isn't being diverted to flow over it). This is a really good write up to follow along -

https://azoffroading.com/blog/jeep-j...r-replacement/

 

Thanks for the link to the write up, have to run over to the parts store tonight and see if they have one in stock and try to replace it. The 5 AM drives to work are a little chilly in the morning, be nice to fix the heat.

 

Indeed they are! Do you have seat heaters? I put some aftermarket butt warmers in my jeep years ago (WarmSeats off eBay) and they were one of the best things I ever did. You'd be shocked how much use I get out of those in Texas. My jeep is topless the majority of the year, and I'll drive it still when it's 40° in the morning as long as it's warming up a bit during the day. The seat heaters helping keep the core body warm is a game-changer IMO. Heck, with no doors even 60-70° can be a bit cool at highway speeds.

 

So i ended up getting a dorman blend door actuator and proceeded to install it. After fighting to install it i plugged the old unit back in, while hanging from the dash, and it was working. I then started taking measurements and the Dorman case is thicker then the stock Mopar unit. Needless to say the old one is reinstalled and working, if i run into issues ill bite the bullet and get a Mopar one which is $90 vs the $20 dorman, well i know the Mopar fits and the Dorman doesnt.

During all messing around i ended up finding this under the dash.


Come to find out its part of a remote start, if you remove the ground from it the jeep would not start its not the entire remote start. So i ether leave it be, figure out the parts that are missing as i dont even have a key fob, or figure out how to remove it. Seems there are only 4-5 wires but they all go up into the steering column. So i now have that going for me

 

So you think the original one was indeed "stuck" or not working but it woke back up and you're now getting heat from the vents after getting the same unit re-installed?

 

Before even removing it i unplugged the power from it and plugged the new one in just to make sure i was indeed getting power at the plug. I then removed the Mopar one and went to install the Dorman unit which i struggled for about 20 min till i stated measuring the outside case and found out the Dorman has a slightly different design and is about 1/8" thicker. After that struggle i then plugged the Mopar unit back in and it was working. Put the arm back on the Mopar unit and reassembled, cycled the door multiple times turned the jeep on and off, everything seems to work. Turned on the jeep this morning flipped it to heat and everything was right with the world.


So yeah no idea why it wasn't working but the old one is back in the jeep. Auto parts store would not take the new one back since i had plugged it in, but hey ive spent $20 in worse places. And i now have a backup for parts if this one does fail again. Ill have to crack them open and see if i can swap the insides and make it work, if not then its back to a Mopar part for sure.