Member Since: 15 Dec 2013
Location: Minnesota
Posts: 4
Stepper blend door motor problem?
Hello all
I am in the process of figuring out what is wrong with my RRS. I have a 2007 RRS US LHD none-SC.
My entire left driver side blows only cold air and in any zone. The passenger side blows warm air in any zone as it should. I did my research on 3 different RR and Disco forums and I know the culprit had to be either the entire HVAC unit or the left blend step door motor is not functioning correctly. I removed the motor and the white plastic moved a long when I turned the dial. I was also able to manually turn the flap door it self but with no luck since I still have cold air in both settings.
How can I eliminate if there is something broken or if there is something stuck in the door? I have removed my entire arm rest, center console, NAV, Radio, heater controls and most of the dash. I am also making a DIY and will post it here once I complete the job.
Any information will help.
17th Dec 2013 4:28 pm
Robbie
Member Since: 05 Feb 2006
Location: ¯\_(ツ)_/¯
Posts: 17932
Welcome to the forum!
Sorry you have had to take so much apart. For diagnosis a fault code reader can help but the biggest must-have tool for HEVAC diagnosis is a cheap USB borescope. They cost about $30 and not only save time with disassembly but you get to see the operation of the actuators/flaps in situ. They key fact is that they can sometimes behave differently when on the bench to actually fitted.
On the D3 HEVAC you can force it into a self-test mode that also reset the position of the actuators when they go out of calibration. I'm not sure how to do this with an RRS but someone may know.
My cheapo USB borescope:
Click image to enlarge
Land Rover - Turning Drivers into Mechanics Since 1948
Member Since: 15 Dec 2013
Location: Minnesota
Posts: 4
What does the borescope do? is it a camera on one end?
I did perform a self reset/test with the motor disengaged from the blend door and it caused the programe button to flash. I can not read the fault code because nothing shows up on the NAV self screen test.
I personally can not understand why it is blowing cold air when I manual turn the flap door gear in both directions and that is why I am thinking something is in the way.
17th Dec 2013 5:16 pm
Robbie
Member Since: 05 Feb 2006
Location: ¯\_(ツ)_/¯
Posts: 17932
Yes, a USB borescope is a narrow illuminated camera on the end of a flexible/malleable rod; the other end plugs into your computer and with the software provided shows you TV pictures of the insides of your vents...Land Rover - Turning Drivers into Mechanics Since 1948
Member Since: 15 Dec 2013
Location: Minnesota
Posts: 4
I see.
So has anyone seen a situation where the motor turns as it should but there is still no difference in the temperature? It's still cold on one side and hot on the other?
Thanks
18th Dec 2013 2:07 am
NickJ
Member Since: 11 Oct 2010
Location: there's no f in point
Posts: 2137
I've had two motors fail, and to be honest once replaced everything worked fine afterwards.
18th Dec 2013 8:22 am
sheefo2k
Member Since: 15 Dec 2013
Location: Minnesota
Posts: 4
When they failed, did they completely not move? or did they throw a code? How did you know your motors failed? I really hope that is what is wrong with my motors but mine turn slowly.
18th Dec 2013 8:26 am
NickJ
Member Since: 11 Oct 2010
Location: there's no f in point
Posts: 2137
When the first one failed there was no air coming out of the windscreen vent at all. When the second one went there was no temperature control on the drivers side. I don't know what fault codes there were as at the time I didn't have a fault code reader.
Sorry, have you tried connecting new motors?
18th Dec 2013 7:30 pm
Bob.
Member Since: 05 Apr 2009
Location: 52�N 2�W
Posts: 94
Robbie wrote:
On the D3 HEVAC you can force it into a self-test mode that also reset the position of the actuators when they go out of calibration. I'm not sure how to do this with an RRS but someone may know.
Quote from the RRS manual:
Distribution motor self-test
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.
21st Dec 2013 10:43 pm
Oswiperus D3 Decade
Member Since: 02 Apr 2010
Location: Chelmsford, Essex
Posts: 1597
when I had no air to the windscreen the self-test didn't reveal any errors however the fault code reader pointed to the correct stepper motor. Even with the dash stripped down as you have already done it's still a to change them, On your back, head rammed under the dash with trying to get your fingers to the motors! Having said that, it's fully do-able. I changed all four motors while it was stripped to save another strip down.
This was the minimum I had to removed in order to gain access to all four motors.
21st Dec 2013 11:34 pm
NickJ
Member Since: 11 Oct 2010
Location: there's no f in point
Posts: 2137
Yes, I agree with Oswiperus above. That's what the dashboard's going to look like after the stripdown. The two on the drivers side are the worse to get to. Best option is definately to change all four at the same time; my second one failed a few months after replacing the first one, and stripping the dashboard again isn't much fun.
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to change them, On your back, head rammed under the dash with trying to get your fingers to the motors! Having said that, it's fully do-able. I changed all four motors while it was stripped to save another strip down.
