No Heat on Passenger Side.

[PCA4208]

Reading through more than a few threads Ive found many have almost the same issue but they have no heat for the Driver side. I have the opposite problem, I just found out yesterday that the passenger side just blows cold, almost as if its on vent or only recirculate. Driver side works great, defrost works well too. I don't think it's a heater core issue as most have stated that a plugged heater core will cause no heat to drivers side.

I do have the dual zone system so I'm afraid its the blend door or actuator which would require me to remove the whole dash to even check. I don't hear any clicking as some have stated, and the AC works perfectly on both sides so this is throwing me for a loop.

Any help is appreciated, almost makes me regret selling my 2006 which had the best heat of any car/truck I've owned lol.

 

[PCA4208]

One more update, just went outside and without the engine running or radio and tried each function. With the fan on lowest setting I turned on and off each face, face/feet, feet, and defrost. Then I moved the driver temp slowly to cold and back up to hot and same with passenger side. On each function I could hear the actuators working very audibly. However on the passenger I heard nothing. No actuator noise, no clicking, nothing. I have no CEL so idk if the actuator is bad or what is going on.


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[Fast69Mopar]

Reading through more than a few threads Ive found many have almost the same issue but they have no heat for the Driver side. I have the opposite problem, I just found out yesterday that the passenger side just blows cold, almost as if its on vent or only recirculate. Driver side works great, defrost works well too. I don't think it's a heater core issue as most have stated that a plugged heater core will cause no heat to drivers side.

I do have the dual zone system so I'm afraid its the blend door or actuator which would require me to remove the whole dash to even check. I don't hear any clicking as some have stated, and the AC works perfectly on both sides so this is throwing me for a loop.

Any help is appreciated, almost makes me regret selling my 2006 which had the best heat of any car/truck I've owned lol.

You are correct in your thinking that you may have an issue with the right side blend door or the actuator. HVAC problems do not trigger the MIL so the only way to know if there are HVAC DTC's is by connecting a scan tool and selecting the HVAC controller to see if there are any active or stored DTC's.

Once a scan tool is connected you can perform the HVAC calibration to see if it passes and you can actuate the right blend door to see if it responds.

 

[PCA4208]

Any idea where to find one of those scan tools that can recalibrate the HVAC? The old one I had really only told engine codes and nothing more. It’s also lost lol.


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[PCA4208]

Any idea where to find one of those scan tools that can recalibrate the HVAC? The old one I had really only told engine codes and nothing more. It’s also lost lol.


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Or can Alpha OBD do this? I’m debating buying it as I have a Bluetooth ELM 327 OBD interface laying around.


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[Ricks Ram]

Or can Alpha OBD do this? I’m debating buying it as I have a Bluetooth ELM 327 OBD interface laying around.


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The Alfa tool can definitely check your HVAC system for DTC codes and run diagnostics. I'm not sure if the ELM327 will be able to connect to the actual modules in your truck like the OBD Link by ScanTool. Unfortunately it appears that your passenger side blend door is not moving. If you are able to confirm it's a blend door motor issue with the Alfa tool and you aren't able to recalibrate it or get it to function it may possibly be bad. This motor in on the back side of the HVAC box directly behind the motor on the front side of the HVAC box that controls the driver's side temp. This motor is directly behind the glove box. You would need to pull the dash and move the HVAC box back as far as possible without disconnecting the the A/C lines to access the motor. It honestly isn't as hard as it sounds. There are videos on YouTube that detail pulling the dash out of the 4th gen Ram. Definitely make sure you check for codes and run as many diagnostics as possible before you decide to actually replace the motor. It could also be an issue with the HVAC module itself or the wiring.

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[SitKneelBend]

Or can Alpha OBD do this? I’m debating buying it as I have a Bluetooth ELM 327 OBD interface laying around.


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I'm pretty sure it can. If you ask the question in the main thread for AlfaOBD someone may chime in.

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[PCA4208]

The Alfa tool can definitely check your HVAC system for DTC codes and run diagnostics. I'm not sure if the ELM327 will be able to connect to the actual modules in your truck like the OBD Link by ScanTool. Unfortunately it appears that your passenger side blend door is not moving. If you are able to confirm it's a blend door motor issue with the Alfa tool and you aren't able to recalibrate it or get it to function it may possibly be bad. This motor in on the back side of the HVAC box directly behind the motor on the front side of the HVAC box that controls the driver's side temp. This motor is directly behind the glove box. You would need to pull the dash and move the HVAC box back as far as possible without disconnecting the the A/C lines to access the motor. It honestly isn't as hard as it sounds. There are videos on YouTube that detail pulling the dash out of the 4th gen Ram. Definitely make sure you check for codes and run as many diagnostics as possible before you decide to actually replace the motor. It could also be an issue with the HVAC module itself or the wiring.

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Yep, the rear motor is what I'm afraid it is and have read horror stories of dealing with it. Im comfortable enough mechanically to remove the dash, truthfully just would rather not as it seems like a hassle as I have the full center console as well. I inquired over on the Alpha OBD thread so hopefully someone over there can answer my questions as well.

 

[Ricks Ram]

Yep, the rear motor is what I'm afraid it is and have read horror stories of dealing with it. Im comfortable enough mechanically to remove the dash, truthfully just would rather not as it seems like a hassle as I have the full center console as well. I inquired over on the Alpha OBD thread so hopefully someone over there can answer my questions as well.

I've pulled the dash out of my 14 plus another 15 to actually install the Dual Zone ATC. It really wasn't that bad. If you're mechanically inclined you should be fine. It's better if you have someone help you to avoid scratching any interior pieces or upholstery. Also make sure you are careful to protect the leather steering wheel. I covered mine with a thick towel.

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