Jeep Heat Broke

[Jk.Overland]

So of course right as winter is here my heat has gone out in my 2012 Jeep Jk. I knew I needed to replace my Blend Door Actuator, I did that. Then I checked and topped off my coolant. Still no heat.

Any Jeep JK owners out there have this issue in the past and got it fixed?? Any help?

I have a trip planned to go hit some Badge of Honor Trails in Arkansa in December but I have to have heat to make this trip.

 

[reaver]

No experience with jeeps, but check to see if you have liquid on the floor. If so, chances are your heater core has gone out.

Other than that, I've got no clue.

 

[North American Sojourner]

There are 2 hoses entering the heater box through the firewall. Check the temperature on each line. Use a digital temp gage if possible. It should vary from hot to warm. I think jeep uses a heater control valve. Make sure valve is operating (opening and closing).

 

[PCO6]

There are 2 hoses entering the heater box through the firewall. Check the temperature on each line. Use a digital temp gage if possible. It should vary from hot to warm. I think jeep uses a heater control valve. Make sure valve is operating (opening and closing).

I'm not sure if they went back to it for the JK's but Jeep did away with the heater control valve when the TJ's came out in late 1996 and also deleted them on XJ's at the same time. It's common to remove them from earlier model XJ's and rely on the dashboard controls to operate the blend door.

@Jk.Overland - Have you flushed & back flushed your heater core?

 

[Prerunner1982]

It wouldn't happen to be blowing cold on the driver side and warm on the passenger side would it?
That is a common issue with casting sand that was not removed from the engine properly clogging up the heater core on one side.
Replacing the heater core typically involves removing the dash however there is a "hack" that saves loads of time. Heater Core Swap in 30 Mins

 

[rho]

It wouldn't happen to be blowing cold on the driver side and warm on the passenger side would it?
That is a common issue with casting sand that was not removed from the engine properly clogging up the heater core on one side.
Replacing the heater core typically involves removing the dash however there is a "hack" that saves loads of time. Heater Core Swap in 30 Mins

Any resolution to this OP? Casting sand was a common thing for early 3.6 motors. A couple other possibilities include: air trapped in the heater core, Tstat gone out or other FOD obstruction into the cowl airtake or lower air ducts.

Getting the heater core bleed fully is a bit of a pain, but if you hear a 'gurgling' or 'running water' sound behind the dash that is a good indicator that there is a pocket of air in the heater core.

Another possibility is that the blend door might not be installed in the correct orientation relative to the position of the actuator. I'm not familiar enough with the HVAC internals on the jk to explore that possibility more than trying a bunch of google searches or to even see if its a valid line of investigation.