LR3 heater problem
#21
03-15-2014, 10:00 PM
#22
03-16-2014, 03:56 PM
#25
11-07-2014, 12:02 AM
Pro Wrench
Try the self test as below before ....
Look at my post 12 on page 2 of this thread. The info is there plus open the link for pdf files etc on the heating system.
Replacing the stepper motors is no fun task so spend some time understanding the system before you start tearing it apart. The self test procedure as below can sometimes fix a stepper motor problem if you are lucky.
Below is a service procedure from a Land Rover HVAC service instruction sheet. Note also my comments below as to how the procedure actually worked for me.
The motor and flap operation can be checked using the on-board distribution motor self-test function.
The self-test can be initiated by pressing and holding the ECON and RECIRC buttons while turning the ignition switch to the ON position.
The control module will then compare the current motor position with the values stored in the module and will indicate an error by flashing the ECON LED (light emitting diode).
If there are no errors, the LED will go out and the system will function normally.
To confirm that there are no errors, turn the ignition switch to the OFF position, then back to the ON position.
Observe the operation of the programmed defrost LED.
If there are errors present, the programmed defrost LED will flash and the system will attempt to calibrate itself.
My experience was when I did above as described, with the two buttons held down, the ECON light flashed as soon as the ignition was turned on, (engine off), and stayed flashing for nearly a minute or so and then sometimes either just went out, or the fan just started up normal like and the ECONO light went out.
Then when I let go of the buttons and turned the ignition off and back on, the defrost LED stayed off as if there were no problems - never did I see the defrost LED on.
I did the test procedure two or three times and figured it failed to do anything but now I am not so certain.
Maybe the weather has just warmed up; only -20C today and cloudy, snow tonight however, but now the interior of the 3 seems to warm up more like I recall it used to - fairly quickly.
Also I did some other button pushing - that was cycle a few times, each of the air up, middle air, and foot well air switches that are mounted on the left side. I started with the heater on Auto showing the two little round LEDs illuminated on the fan control; then pushed the left upper air button and let the fan run for maybe a minute; then pushed the middle button and pushed off the upper, and let the fan run for a minute or so; then the foot well button and turned off the middle button.
I did that a few times, each time seeing if air would flow out of the appropriate vents. I also manually turned the fan up to full speed so that when air did flow, there was a real blast.
What I was doing was manually trying to cycle the air doors on the chance that one or more doors just might be sticking and would perhaps un-stick themselves.
I think I may have solved a problem even if I was not certain I had one.
A month ago, I flashed the HVAC software with some newer software and that has really improved the operation of my heating system. The windscreen sunlight sensor now seems to notice the sun and clouds and the auto temp system really is an auto temp system in practice rather than being something that could a good idea if it worked.
This means I do not fiddle with the heat or fan controls to the degree that I used to - pretty much set and forget now.
Replacing the stepper motors is no fun task so spend some time understanding the system before you start tearing it apart. The self test procedure as below can sometimes fix a stepper motor problem if you are lucky.
Below is a service procedure from a Land Rover HVAC service instruction sheet. Note also my comments below as to how the procedure actually worked for me.
The motor and flap operation can be checked using the on-board distribution motor self-test function.
The self-test can be initiated by pressing and holding the ECON and RECIRC buttons while turning the ignition switch to the ON position.
The control module will then compare the current motor position with the values stored in the module and will indicate an error by flashing the ECON LED (light emitting diode).
If there are no errors, the LED will go out and the system will function normally.
To confirm that there are no errors, turn the ignition switch to the OFF position, then back to the ON position.
Observe the operation of the programmed defrost LED.
If there are errors present, the programmed defrost LED will flash and the system will attempt to calibrate itself.
My experience was when I did above as described, with the two buttons held down, the ECON light flashed as soon as the ignition was turned on, (engine off), and stayed flashing for nearly a minute or so and then sometimes either just went out, or the fan just started up normal like and the ECONO light went out.
Then when I let go of the buttons and turned the ignition off and back on, the defrost LED stayed off as if there were no problems - never did I see the defrost LED on.
I did the test procedure two or three times and figured it failed to do anything but now I am not so certain.
Maybe the weather has just warmed up; only -20C today and cloudy, snow tonight however, but now the interior of the 3 seems to warm up more like I recall it used to - fairly quickly.
Also I did some other button pushing - that was cycle a few times, each of the air up, middle air, and foot well air switches that are mounted on the left side. I started with the heater on Auto showing the two little round LEDs illuminated on the fan control; then pushed the left upper air button and let the fan run for maybe a minute; then pushed the middle button and pushed off the upper, and let the fan run for a minute or so; then the foot well button and turned off the middle button.
I did that a few times, each time seeing if air would flow out of the appropriate vents. I also manually turned the fan up to full speed so that when air did flow, there was a real blast.
What I was doing was manually trying to cycle the air doors on the chance that one or more doors just might be sticking and would perhaps un-stick themselves.
I think I may have solved a problem even if I was not certain I had one.
A month ago, I flashed the HVAC software with some newer software and that has really improved the operation of my heating system. The windscreen sunlight sensor now seems to notice the sun and clouds and the auto temp system really is an auto temp system in practice rather than being something that could a good idea if it worked.
This means I do not fiddle with the heat or fan controls to the degree that I used to - pretty much set and forget now.
#27
11-07-2014, 08:14 PM
#28
11-07-2014, 10:58 PM
Pro Wrench
air bubble / air lock perhaps but ..
I have heard of what you are talking about - hot on passenger side and cold on drivers side.
Some think the problem is an air lock within the heater core. If so, it seems about the only way to get the air out seems to be to run the engine with both front and rear heaters on full manual hot for a couple of hours or so.
Myself, I cannot believe that an air lock or a defective heater core makes hot air come out one side and cold the other. To me, the only thing that would do that is an internal air door stuck so outside air goes one route and heated air the other.
As such, I would be looking at the operation of the air door operated by the Footwell Stepper motor, old part number JWO50020, and now LR041272.
I assume you have the automatic system where the left side rotary **** is capable of setting the drivers side at one temperature and the right side **** controls the passenger side temp. (Manual is supposed to do that as well.) I assume you have rotated the left side **** to full hot and the right side to full cold in an attempt to get the heat to shift sides from what is happening now.
My understanding is that the split system can only achieve a 2 degree C, (5 degrees F), difference in temperature side to side but ...
If you have one of those old type glass mercury thermometers, you might try setting it in the various heat ducts to see if the reading changes when you fool with the *****.
I guess what I am saying is that if the air door is moving as it should, you should see a small difference in the temperature readings. Right now, you have ambient temp on the drivers side and hot on the passenger - does not to me sound like a blocked heater core or air lock but a frozen air door.
Please keep us informed.
Some think the problem is an air lock within the heater core. If so, it seems about the only way to get the air out seems to be to run the engine with both front and rear heaters on full manual hot for a couple of hours or so.
Myself, I cannot believe that an air lock or a defective heater core makes hot air come out one side and cold the other. To me, the only thing that would do that is an internal air door stuck so outside air goes one route and heated air the other.
As such, I would be looking at the operation of the air door operated by the Footwell Stepper motor, old part number JWO50020, and now LR041272.
I assume you have the automatic system where the left side rotary **** is capable of setting the drivers side at one temperature and the right side **** controls the passenger side temp. (Manual is supposed to do that as well.) I assume you have rotated the left side **** to full hot and the right side to full cold in an attempt to get the heat to shift sides from what is happening now.
My understanding is that the split system can only achieve a 2 degree C, (5 degrees F), difference in temperature side to side but ...
If you have one of those old type glass mercury thermometers, you might try setting it in the various heat ducts to see if the reading changes when you fool with the *****.
I guess what I am saying is that if the air door is moving as it should, you should see a small difference in the temperature readings. Right now, you have ambient temp on the drivers side and hot on the passenger - does not to me sound like a blocked heater core or air lock but a frozen air door.
Please keep us informed.
#29
11-08-2014, 05:56 AM
Thanks for the reply bbyer,
Is the footwell Stepper motor depicted as #2 on the AUTOMATIC SYSTEM CONTROL DIAGRAM?
If so, this motor was changed and the problem is still there.
BTW, the rear heater (behind the driver) is the same temp as the driver.
While the rear heater behind the passenger is the same as the passenger (much warmer).
I am kinda stumped at this point.
Is the footwell Stepper motor depicted as #2 on the AUTOMATIC SYSTEM CONTROL DIAGRAM?
If so, this motor was changed and the problem is still there.
BTW, the rear heater (behind the driver) is the same temp as the driver.
While the rear heater behind the passenger is the same as the passenger (much warmer).
I am kinda stumped at this point.
#30
11-08-2014, 10:46 AM
Pro Wrench
left hand drive vs right hand drive heater designs
The ducting diagram below shows the ducting for the front located heater.
When I referred to rear heater, I mean the optional heater/AC unit physically located in the left rear of the 3 in the boot area. If you have the 5 seater, then you would not have the rear setup and perhaps not on the 7 seater either.
The air outlet I think you referred to is called up as a register and are the ones called up as 10 in the link pdf. They take their air from the front system. It would be reasonable that the air from the console located registers would ape the front air. This also applies to the outlets under the front seats.
http://www.disco3.co.uk/gallery/albu..._Operation.pdf
One of the problems with LR is that often the diagrams we look at are for the RH UK driver vehicles. The drawing I am looking at here and I expect it is the same one you have shows the heater for the UK vehicles with the fan located on the left end. Our LH driver versions have the fan located on the right end.
Re the Automatic System diagrams, the #2 stepper motor, and also the #5 stepper motor, which are both called on the diagram as temperature blend door motors and I think one or the other or both are the problem, (if is a motor problem); but both is unlikely.
I expect the motor located on the fan side is for the Right Hand temperature blend door, but that is not clear to me due to the reverse designs.
As such, that motor you removed was I suspect working OK and is I think was probably on the right side, (the fan side), of the air unit. I gather however that a failure in one motor can cause everything to stop working, hence replacement can be a trial and error thing. I think the #2 and #5 motors are the same part number so you might try putting the removed motor in the #5 location assuming you can get at it. Access down there is near impossible. As such, there is an argument to change out any and all motors you can get at because it is such a problem to access them. The bottom two are the only ones you can possible get at in any practical sense but I think this is where the problem is so you are "fortunate" in that sense.
When I referred to rear heater, I mean the optional heater/AC unit physically located in the left rear of the 3 in the boot area. If you have the 5 seater, then you would not have the rear setup and perhaps not on the 7 seater either.
The air outlet I think you referred to is called up as a register and are the ones called up as 10 in the link pdf. They take their air from the front system. It would be reasonable that the air from the console located registers would ape the front air. This also applies to the outlets under the front seats.
http://www.disco3.co.uk/gallery/albu..._Operation.pdf
One of the problems with LR is that often the diagrams we look at are for the RH UK driver vehicles. The drawing I am looking at here and I expect it is the same one you have shows the heater for the UK vehicles with the fan located on the left end. Our LH driver versions have the fan located on the right end.
Re the Automatic System diagrams, the #2 stepper motor, and also the #5 stepper motor, which are both called on the diagram as temperature blend door motors and I think one or the other or both are the problem, (if is a motor problem); but both is unlikely.
I expect the motor located on the fan side is for the Right Hand temperature blend door, but that is not clear to me due to the reverse designs.
As such, that motor you removed was I suspect working OK and is I think was probably on the right side, (the fan side), of the air unit. I gather however that a failure in one motor can cause everything to stop working, hence replacement can be a trial and error thing. I think the #2 and #5 motors are the same part number so you might try putting the removed motor in the #5 location assuming you can get at it. Access down there is near impossible. As such, there is an argument to change out any and all motors you can get at because it is such a problem to access them. The bottom two are the only ones you can possible get at in any practical sense but I think this is where the problem is so you are "fortunate" in that sense.