HVAC Cabin Air Circulation Not Turning On

[USMC_315]

Hey guys,

Starting up the H3 today and getting it ready for the snowstorm about to hit our area. I noticed last time I drove it and today again that the air circulation button doesn't do anything anymore. The light comes on for cabin recirculation, but I can tell it doesn't actually engage. Any thoughts on what may be causing this? If I'm not mistaken I think I had the HVAC motor recently replaced in the past year or so... Any thoughts would be of great help, I hate the smell of napalm in the morning :giggle:

 

[Jeepwalker]

Did your tk go into 'recirculate' in past winters? Or earlier in the year? Did it work after the blower motor was replaced? Does the blower motor work at all speeds? Could be a faulty blend door motor. You probably don't have a good scan tool to test, do you?

This isn't a problem I've had to deal with directly but these are the steps I'd do if it were me: If you haven't done so already, go to the link below (about 1/3 down the pg) and read the 'how it works' of the HVAC link ...in the factory manual. Learn the sequence of what is supposed to exactly occur, step by step, when ya engage the Recirculate feature. There's a whole troubleshooting section on the sub-systems and the controller. Should help you debug the system. For example, it might not work if the refrigerant is low (I don't know that or sure, but just 'sayin' some factors could be interconnected).

Find the recirc damper motor and Ohm it out. Remove and feel if the hvac door is rotating and closing properly, all the way. You might have to lightly use a pliers (e.g. I have a Jeep where the outside/recirculate damper is literally broken off the shaft inside the housing). If the damper motor tests fine, swap another damper motor in it's place. If all that seems fine, wiggle the hvac fuses and the wire harness on the HVAC controller. Make sure the connector pins aren't bent. Before you condemn the controller, might be worth disconnecting the battery cables, and bring in the hvac controller into the warm house overnight or longer, to let the circuits drain out (reset). Then re-try. Sounds crazy, but it works when the door module goes flaky. I've had to do it a couple times.

https://schwarttzy.com/h3-hummer/

(note: the manual pages seem essentially backwards. My suggestion is to read each page from the bottom (the beginning) to the top)

 

[Jeepwalker]

I read through the H3 HVAC section. Basically it says to lower glove box from its attachments (just lower the door). You will see the actuator for the recirculation door behind it. Engage Recirculate switch and observe hvac recirc motor. If need be, remove connector and put a test light on the wires (to ground) and engage and look for it to 'light' as ya drive the motor open & closed (via the switch). Remove motor and test that the door shaft (and door) operates smoothly and bottoms out properly. The Recirculate section is about 3/4 of the way down on the HVAC 1 portion of the manual. (link above)


Note ...from the manual:
ACTUATOR RECALIBRATION
When replacing an air temperature, mode, recirculation actuator or the HVAC control assembly,
the following calibration process needs to be performed:
1. Turn ON the ignition with the engine OFF.
2. Turn the Temperature dial all the way to the right.
3. Turn the blower control dial all the way to the right.
4. Turn the mode position dial all the way to the left.
5. Simultaneously press and hold the A/C and Defrost buttons until the LED's start to flash.
6. Once the LED's stop flashing, calibration is complete.

Let us know what the issue turns out to be. Probably a failed motor I'm guessing.

 

[Jeepwalker]

In the General Description (bottom of HVAC pg of manual -- link above):

Recirculation Operation
The recirculation actuator is a 2-wire bi-directional electric motor. Two control circuits enable
the actuator to operate. The control circuits use either ground or a 12-volt value to coordinate the
actuator movement. The HVAC control assembly reverses the polarity of the control circuits to
move the actuator in the opposite direction. The recirculation operation can function with blower
motor in either the ON or OFF position. Recirculation is not available in Defrost and Mix-Blend
mode. If an operator requests recirc in defrost or mix blend the recirc LED will flash 3 times and
then turn OFF. The system will remain in fresh air mode.

 

[alrock]

Sounds like a dead actuator. I've replaced other ones but not that one but they are generally easy to get to. When you do replace one you need to do the reset above, or simply disconnect the battery for a minute or so and reconnect and the H3 will do the reset.

 

[USMC_315]

Thanks for the tips fellas. I'll get on this soon, hate smelling diesel exhaust all the time lol

 

[USMC_315]

Did your tk go into 'recirculate' in past winters? Or earlier in the year? Did it work after the blower motor was replaced? Does the blower motor work at all speeds? Could be a faulty blend door motor. You probably don't have a good scan tool to test, do you?

This isn't a problem I've had to deal with directly but these are the steps I'd do if it were me: If you haven't done so already, go to the link below (about 1/3 down the pg) and read the 'how it works' of the HVAC link ...in the factory manual. Learn the sequence of what is supposed to exactly occur, step by step, when ya engage the Recirculate feature. There's a whole troubleshooting section on the sub-systems and the controller. Should help you debug the system. For example, it might not work if the refrigerant is low (I don't know that or sure, but just 'sayin' some factors could be interconnected).

Find the recirc damper motor and Ohm it out. Remove and feel if the hvac door is rotating and closing properly, all the way. You might have to lightly use a pliers (e.g. I have a Jeep where the outside/recirculate damper is literally broken off the shaft inside the housing). If the damper motor tests fine, swap another damper motor in it's place. If all that seems fine, wiggle the hvac fuses and the wire harness on the HVAC controller. Make sure the connector pins aren't bent. Before you condemn the controller, might be worth disconnecting the battery cables, and bring in the hvac controller into the warm house overnight or longer, to let the circuits drain out (reset). Then re-try. Sounds crazy, but it works when the door module goes flaky. I've had to do it a couple times.

https://schwarttzy.com/h3-hummer/
(note: the manual pages seem essentially backwards. My suggestion is to read each page from the bottom (the beginning) to the top)

My HVAC has always gone into recirc up until a few weeks prior to me posting that. I don't know if it sitting for several months without driving caused the issue. I was able to see the actuator is working properly. The white dial or whatever is turning when I engage/disengage the button on the controls. It must be the actual door itself. I can't seem to figure out how to get to that door. From my understanding of the linked diagram(s), it is up behind the airbag. So without removing the dash, it seems impossible. Unfortunately I do not have the space right now to remove the dash and other components in order to get to the housing with the recirc door.

 

[DJB]

Old post, but for future reference: Recirculation is available only in the bi-level and vent modes. Not available in floor, floor/defog or defrost modes. I had the same problem so I grabbed the owner's manual and checked it out. My blend door and mode actuators are getting a bit lazy (have to overshoot and then come back to where I want) so I'm planning on replacing all three.

 

[USMC_315]

Old post, but for future reference: Recirculation is available only in the bi-level and vent modes. Not available in floor, floor/defog or defrost modes. I had the same problem so I grabbed the owner's manual and checked it out. My blend door and mode actuators are getting a bit lazy (have to overshoot and then come back to where I want) so I'm planning on replacing all three.

I'm aware of that, this is happening in one of the allowed modes though. Like I mentioned, the actuator engages and the white gear looking thing viewable from the outside turns as it should under normal operation. That's why I believe it is the actual door mechanism that's causing the problem. Let me know how long/difficult it is to get to the actuator for the recirculation though, it looks like the whole dash will have to come off to get to it...

 

[Lalo]

I'm aware of that, this is happening in one of the allowed modes though. Like I mentioned, the actuator engages and the white gear looking thing viewable from the outside turns as it should under normal operation. That's why I believe it is the actual door mechanism that's causing the problem. Let me know how long/difficult it is to get to the actuator for the recirculation though, it looks like the whole dash will have to come off to get to it...

Did you resolve the issue. We got a H3 , actuator works but door seems not to close at all.

 

[USMC_315]

Unfortunately no, it seems to be the door that is stuck open and apparently the only way to get to it is to remove the entire dash. It's not worth the time or money to me right now to fix it or get it fixed. If you find another, easier solution, let me know though!

 

[Jeepwalker]

I haven't had one go bad on my H3 (yet) ...but I have a Jeep G/C that I think I've replaced 4 of them over the years... All easy to access fortunately.