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Hi, I would like to ask how difficult, in real life experience, is it to remove the dashboard display unit, in a UK [RHD] vehicle.

I believe that there are 4 Phillips screws holding up a plastic panel under the steering wheel but then there is a metal frame inside the dashboard cavity. Some people have said to remove the metal frame, but it is a real pain both to remove the bolts and to re-locate it when re-assembling. Other people have suggested just loosening the bolts a bit, but don't remove completely.

Again, I believe that the dashboard display is held in by 4 screws, and the unit should pull out over the steering wheel cover. Am I correct in this.

Lastly, do I need to disconnect the battery before doing this, I suppose it makes sense to do so.

Any help/suggestions much appreciated.

Pierre3.

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I’ve only removed one from a parts P38, LHD. I just followed Rave and it went fine. I would definitely disconnect the battery if it was me.

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It’s a bit involved but just go methodically. Hardest part is not breaking clips on windscreen panel and at the end the heavy part of removing it! 2 strong people required. I think you have to degas the A/C too… might be wrong…

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If you mean the binnacle unit itself, then it is a 5 minute job. Remove the kick panel, remove the binnacle surround, remove the four screws holding the binnacle, unplug the connectors, out. DO NOT turn on the ignition without the connectors plugged in.

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I removed ours yesterday to change the heater matrix… there’s a lot of stripping but it’s not actually that bad a job to be honest.

This guide is great. I followed it on my iPad and it was spot on.

http://paulp38a.com/range-rover-p38/dash-removal/

David.

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If you mean the whole dashboard, follow the guide that David H posted. If you just want to remove the instrument cluster, as the other David says, it's a 5 minute job.

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Thanks for the replies, everyone. I will have to get into the underside of the dashboard to fit new blend motors. I have to think about what I need to get to do the job when the weather improves in the spring.

One thing I would like to ask - I often see adverts showing three motors together. So does that mean that there are three blend motors in total, or are there three blend motors for each side ?

Pierre3.

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3 in total, one on each side for the temperature and another on the RH side (easily seen with the instrument cluster out) for the air direction.

See https://web.archive.org/web/20180509124955/http://www.rangerovers.net/repairdetails/blendmotor.html although that makes it look more difficult than it is. No need to remove the ducting, all you need is a right angle screwdriver.

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No need to remove the ducting, but it has probably pulled apart anyway! It's well worth having a roll of duct tape to hand, even if it's just for the satisfaction of seeing it used for it's intended purpose :)

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Thank you guys. Funnily enough I do actually have a right-angled screwdriver !!! I got it made when I used install big glass revolving doors, and very useful indeed. A friend of mine made it with a small universal joint and a socket for screwdriver heads on one end and a 3/8th drive head on the other end.

I will have to look for a set of blend motors now, but I have some time because, unfortunately, I have to do all my work on the drive - outside :(.

I did notice that a guy called William Chetwynd advertised a set on his Facebook page last July, or thereabouts. I didn't know that I needed them then !!

Pierre3.

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https://www.canadiantire.ca/en/pdp/mastercraft-bit-wrench-set-29-pc-0588626p.html#srp
This little 90* ratcheting screw driver is very handy. I’m sure there are other non-Canadian suppliers out there.

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Very similar to the set I have, invaluable at times.

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just before you replace your blend motors are they actually burnt out or just unable to move because your heater box has shrunk and the little 7.2v motors haven't the guts to move them, if this is the case new motors wont fix it , you will have to modify the heater box and loosen it up by dismantling it and sanding the inside of the box to loosen it up. motors are expensive if you buy new , i just picked up old second hand ones for nothing in case i needed parts to fix . after fixing the heater box i just reused the old ones , all is working fine still .
PS when i removed the screws for the motors i used a small screw driver and just taped the screw to the screw driver, very easy. the flaps in the heater box will move with the flick of a finger when you fix the heater box. my vehicle is a RHD if that makes a difference.

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I've found the usual problem with blend motors is the feedback pot goes open circuit. Sometime a squirt of contact cleaner sorts them but not always. There's so much reduction gearing in them that the flaps have to be really stiff to stall the motors.

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I was afraid that the issue of the heater box would be mentioned [oh no, no, no, please not the heater box] but hopefully Richard is right and it's the blend motors.

As I have a shiny new Nannycom will using this give me a better idea of what is happening ? What will Nanny tell me that using the actual controls in the car won't ?

Thanks for your comments, Mad-as, I will have to bear this in mind.

Harv, that's a neat little set.

Pierre3.

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Nanocom won't just give you a better idea of what is happening, it will tell you exactly what is happening. With the engine running, go to HEVAC - Inputs - Values. Scrolling through the pages from there you can read:

· Ambient temperature (c): This reading gives the external air temperature or air entering the ventilation system.

· Aspirator temperature (c): This reading gives internal cabin temperature.

· Evaporator temperature (c): This reading gives the evaporator unit's temperature.

· Heater core temperature (c): This reading gives the engine coolant temperature where the coolant enters the heating system.

· Road speed (Km/h): This value is generated by the ABS ECU using information from its wheel rotation sensors.

· Road speed (mph): This value is generated by the ABS ECU using information from its wheel rotation sensors.

· Engine running:

· Solar sensor (w/sqm): This reading gives the effective strength of the sun as detected by the Solar Sensor mounted beside the Alarm LED on the top of the dashboard.

· Distribution motors (%): This gives the current feedback position of the motor that drives the flap controlling air distribution inside the vehicle. As the distribution buttons are pressed the flap should move to the position which gives air flow to the selected direction (feet, face, screen etc.).

· Left blend motor (%): This gives the current feedback position of the motor which drives the flap controlling amounts of hot and cold air to be blended together (effectively the temperature of the air coming out of the vents). As the requested temperature is changed by the user the flap should move.

· Right blend motor (%): This gives the current feedback position of the motor which drives the flap controlling amounts of hot and cold air to be blended together (effectively the temperature of the air coming out of the vents). As the requested temperature is changed by the user the flap should move.

· Left blower return: This is the feedback value returned back to the Hevac ECU from the left blower motor, used by the ECU to determine the actual voltage at the motor. This reading value also allows the Hevac ECU to detect Blower motor faults.

· Right blower return: This is the feedback value returned back to the Hevac ECU from the right blower motor, used by the ECU to determine the actual voltage at the motor reading. This value also allows the Hevac ECU to detect Blower motor faults.

· Air conditioning grant: When the A/C button is pressed an active low signal is output to the engine management ECU (The Request). This then looks at factors like engine temperature, load, current acceleration etc. and according to when these conditions allow, grant Air conditioning. This involves it engaging the clutch to drive the Air Conditioning pump, altering its internal fuelling to compensate for the load imposed by the pump, managing along with the Hevac the Condenser fans, and also telling the Hevac that Air Conditioning has been granted.

So by looking at the feedback values for the 3 blend motors, you can see that as you change the airflow direction from the HEVAC, the number in that box should change. The same when you look at the feedback from the two temperature blend motors. If you change the temperature from Lo to Hi, you'll see the number in the box change from 0 (or near to 0), up to 100. If the feedback number doesn't change when you cause an individual blend motor to move, either the motor is dead (not that common), it has stalled due to stiff flaps (also not that common in the UK (and nearby) climate, much more common in hotter areas) or the feedback pot has died so not giving an output (most common in my experience).

The same goes for the blowers, you can adjust the blower speed and watch the feedback figure change.

By looking at the reported temperatures from the various other sensors, you can also see if they are giving sensible readings or not as that can also cause problems.

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hi Pierre3 ,just a FYI i spent a week getting around pulling the dash , tried every trick in the book , wasted lots of time dodging it to just pull the dash, and i was done in 2 days. there are several things that i would check before i would do it again
alarms on nano , if you are getting over current readings on the nano that is saying its hard to drive the distribution flaps . as Richard said the motors are toquey but the becm controls the power output not the motor, also i would pull the instrument panel out (RHD) and remove the blend motors and try and turn the flaps on the heater box where the big white wheel is , also remove the wheel and see if that makes a difference to the movement of the flaps as the wheel can also be very tight . i had to take possibly 5mm out of the box to free it up, easy to sand out the areas with a power file or similar. i can now move the flaps in the box with a flick of a finger and i don't hear the motors working any more which would be another little sign that the box has shrunk as they make noise when under load. the hardest part of the dash removal was the strip above the glove box , it would not come off then fell off basically . i used pauls p38 dash removal process , very easy just follow instructions, also i removed one of the stalks from the steering wheel just for more wiggle room .if you need to do it you will wonder why you wasted so much time dodging it
PS you will need 2 people to lift the dash out of the car an to install , be careful as its old and could be i bit brittle so handle the dash with so care. good luck with what ever you end up doing.

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Richard and mad-as, that you both so much for the extensive and very explanatory descriptions. I really appreciate the time that it has taken to type all the detail, especially Richards explanation.

I will print both posts and read them several times to understand the issues. I much prefer paper documents where I can revert backwards to something that I may have missed.

Thanks again, guys.

Pierre3.

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Pierre3 wrote:

Richard and mad-as, that you both so much for the extensive and very explanatory descriptions. I really appreciate the time that it has taken to type all the detail, especially Richards explanation.

No typing at at, just a copy and paste of the Nanocom documentation......

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Well either way, thanks. I appreciate it !

Pierre3.