I have flushed heater core and replaced blend door actuator on drivers side. Inflow pipe temp is 187 degrees and outflow pipe from heater core is 180 degrees, suggesting heater core is working. I sense the heat door closing within the distribution unit is not moving despite engagement with blend actuator and arm moving in response to temp dial change. Any help is appreciated.
2012 Jeep Wrangler Unlimited Sport Heater Not Working
- Thread starter std41085
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Since you've flushed the heater core and replaced the blend door actuator, there are a few other things you could check:
Check the HVAC Control Module: Sometimes, the issue might not be the actuator itself but could be related to the HVAC control module not sending the correct signals to it. You can try a recalibration of the system, if possible. Disconnecting the battery for a few minutes can sometimes reset the calibration.
Inspect the Blend Door: Since you've replaced the actuator, ensure that the blend door itself isn’t stuck. Sometimes, debris or a broken piece can prevent it from moving freely.
Diagnostic Codes: If you have an OBD-II scanner, check for any stored trouble codes that could point to a malfunction in the HVAC system.
Heater Control Valve: If your model has a separate heater control valve, check to make sure it’s opening properly when you set the temperature on the dial.
Ductwork Blockage: Sometimes, debris can block the ductwork leading to the cabin. Check to ensure that there are no obstructions in the vents.
Temperature Sensors: If there are temperature sensors for ambient or cabin temperature, ensure they are functioning properly.
Two things I experienced when I did the heater core flush and had to replace the blender door actuator. I also had no heat. First I burped the coolant to remove the air bubbles. Parked Jeep on an angle with the front end up. Opened radiator cap (when cold). Using funnel added coolant until no more bubbles. Squeeze top radiator hose to help. Be careful, when the engine reaches operating temperature, the coolant will erupt violently . Do this two times. Should remove any air pockets in system.
Second. I found that the blend actuator arm had slipped off the pin that moves the door. I had to remove the pin on the arm. Replac with a small bolt and nut to capture the arm to the blend door attachment. Now the blend door actually works as it is supposed to. Did this before reassembly of all the parts you removed to get to the blend door actuator. Pain in the but to do this twice as I had to.
Lastly, perhaps your control knobs assembly might be bad. Mine was not.
The wife is happy that we now have heat!!!! Hope this helps.
Second. I found that the blend actuator arm had slipped off the pin that moves the door. I had to remove the pin on the arm. Replac with a small bolt and nut to capture the arm to the blend door attachment. Now the blend door actually works as it is supposed to. Did this before reassembly of all the parts you removed to get to the blend door actuator. Pain in the but to do this twice as I had to.
Lastly, perhaps your control knobs assembly might be bad. Mine was not.
The wife is happy that we now have heat!!!! Hope this helps.
Thank you! Great suggestions! I have already purged the air bubbles twice in the coolant system. We have the same issue I think. I think the actual door is not moving like your issue. despite engagement by arm. I have everything open where I can see and didnt re-assemble yet. I will try your idea!