I have a 2006 Range Rover Sport. It is running well, drivetrain is smooth and runs like new....it should, it now has a total of 16k miles on it. However, I am still working on a few gremlins. One is the air and heat controller or associated blend doors. Here are the issues:

Air Conditioning works, but only on the passenger side. Heat will only work on the driver's side if the ECON button is engaged. No face vents, either side, ever.

No Face Vents either side (not blowing, ever regardless of heat, a/c or outside air)
No A/C Drivers Side
No Back Seat Center Console A/C or Heat (no blow)
Windscreen blows both sides, A/C on Passenger side only
Footwell blows both sides, A/C on passenger side only
Back Seat foot vents blow, both sides
No Driver's side heat unless ECON bottom is pushed footwell or windscreen

Any ideas, I don't want to pull the dash apart if I don''t have to. I am thinking that this may be the control unit as opposed to some blend door issues. When I got the truck working again a couple of months ago, the air and heat worked great, no issues at all. About two weeks later, I had the conditions listed above. No codes of any kind. Swapping the control unit isn't the end of the world and is much easier than trying to pull the plenum.......
What are your thoughts............go

One other issue. The headlights had some gremlins. One had dropped to the down position and locked. We got the headlights both pointing straight. They no longer move as you turn the wheel. I am not concerned about that, but there is a flashing headlight on the dash that I would like to extinguish. Is there any way to pull the plug on the flashing dash light that won't impact the headlights? Thanks again. This is a great forum! Phil

 

Blend motors fail more frequently then A/C Control Units. I've also seen stuck blend doors internal to the HVAC box. Due to the location of these components, parts of the dash need to be removed for diagnosis. Electrical problems with a control unit commonly store faults in the memory. Also, installing another HVAC control head requires clearly faults and possibly programming/software update.

Not sure of a way to turn off the headlamp fault like without fixing the problem. Could possibly try adjusting the configuration file for your vehicle, but you would need different headlamps assemblies to go this route; i.e.- halogen headlamps, not HID headlamps.

 

I dug in and removed the lower servo on drivers side. It was plugged in but it was not moving. I manually moved the blend door shaft. I believe that blend door is the temp blend door. Well I am not sure what I triggered but the dash vents started working! I don't seem to have separate temps on the drivers and passenger sides. I can live with that but I would like to figure out what is going on with the servos. Peter. Thanks for the advice! Phil

 

Sorry for jumping in on your thread but I noticed a low humming sound coming from the HVAC that seems to be the blower motor. The noise doesn't increase when the fan speed increases but is most noticeable when the fan speed is the slowest. It reminds me of the hum that used to come from the radio from RF interference or a power steering pump hum. Could this be a sign the blower motor is on it's way out?


Thanx and again, my apologies for hijacking your thread....

 

The blower motor is located behind the lower glove box. You can drop the glove box by pushing in on the two tabs on either side of the glove box. It will allow you to access the fuse panel and the blower motor. You should be able to get a better idea where the humming is coming from. Good luck. Phil

 

May be a sign that it's on its way out, but also could just be due to a build of of carbon dust and other gunk that accumulated on it over the years. Bbyer posted a good writeup of his removal and replacement of the blower motor here.

It could also be that something managed to bypass your cabin air filter and is sitting in the fan blades, making noise. I actually got a piece of duct tape in there once that was loud as all heck.

Regardless, I would try removing and cleaning first since it's not that difficult. After 96,000 miles, I was surprised how much carbon dust there was on mine. Makes me wonder how long those brushes actually last.

 

Below is a LR official test procedure that costs nothing and I guess works, however I cannot say for certain.

I sometimes do it as a routine when I think maybe the air doors are mixed up. I have never actually seen the LED referred to flash, but I have amused myself in thinking that after the procedure, the system seemed to operate better.

HVAC test procedure:

With ignition off, press and hold the ECON & RECIRC buttons whilst turning ignition on, (no need to start car), but I do as that ensures sufficient voltage to run the system computers.

The control module will then compare the current HVAC actuator motor positions with the values stored in the module and will indicate an error by flashing the ECON LED.

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.


Below is a link to a number of HVAC pdf files that may be of interest.

http://www.disco3.co.uk/gallery/thumbnails.php?album=30300

 

I have tried about every configuration on the climate control unit and can't get the blend door servo motor to acutate. It is the lower servo motor on the driver's side of the main hvac box under the dash. Does anyone know if there is a way of testing the motor? I am hoping that it is just the motor and not the climate control unit for the reason stated by Peter above. thanks Phil

 

Well, maybe it is not true that all the motors move temperature blend doors but it seems that way.

Probably the lower motors are what would be termed blend or temperature doors and the upper motors, sort of direct where the air goes.

Normally the problem is the motors and most guys replace the ones they can easily get at. I think the general feeling is that three of the four are possible with the fourth, an upper, best to leave alone and hope it is OK.

In other words, do not worry about the printed circuit boards; they are most often OK, but the motors are commonly at fault.

It also seems that all four motors have to be connected and OK and then it takes a few minutes after startup for them to sort themselves out. What I am saying is that once you do the fix, be patient, it takes time for the computers to sort themselves out and get the doors in sync. That is what that test procedure in my post above is supposed to do but do it a number of times and be patient.

This is not much help, but trial and mostly error seems to be the fix.

Some say LR part # JWO500030 or LR041273 is the air mix door.
Some say LR part # JWO500010 or LR041271 is the defrost motor
Some say LR part # JWO500020 or LRO41272 is the footwell motor
Some say LR part # JWO500010 or JNC500040 is the recirculation motor for LH drive.

 

When you say you can't get the blend motor to actuate, How do you know the motor isn't actuating? Are visually watch the motor movement when adjusting the temperature?

Remove the motor from the box. Make sure the motor is connected to the wiring harness. Adjust the temperature settings. Does the motor arm move?

While the motor is disconnected from the box, move the flap manually. Does the temperature change at the vents?

Report your findings.