Td5 D2 Sunroof- manual to electric.

The twin sunroofs on Hx were originally manually operated and to compliment their fitting, the original owner had specified the leaky sunroof option in the 'only when parked downhill' mode!

I put up with that leaky situation for way too long, spending many an hour reading about solutions and hatching a plan to convert the sunroof operation from manual to electric. Taking the headlining out to trace and cure the leak would provide the perfect opportunity to convert the sunroof to electric operation and I began to plan combining both tasks.

Do the Research.

I found the pages of Rave invaluable in planning what to do. All the components are described, identified, located and the wiring diagrams have all the answers if you stare long enough!

Lots of advice and opinions about the conversion to electric can easily be found on the web pages. All of this web stuff is good to read but you do need to pick and choose reference points and you just cant go wrong with Rave.

The Essentials

Two motors, a little box of tricks, the factory wiring loom and a set of fitted switches are all needed. Fitting the components to the vehicle is easy enough. It really can be a case of plug and play.

Even the final hurdle of switching the BCU to operate and control the circuit can be by-passed if needed. When I was planning the work I did not have a Nanocom to interrogate the BCU and this stage troubled me, but as I worked through it, it became obvious that a direct 12v supply to the power loom would be another option. In the end and by the time I got around to the work, I had saved the pennies and bought a Nanocom.

The Motors

LR part number  -  EGQ100230

These small compact and powerful motors are readily available second hand. Their design and connectivity remained virtually unchanged throughout the entire Discovery D1/D2 production run. I would not be surprised if these motors can be found in other vehicle ranges as well.

Despite having well sealed cases they can suffer from water damage caused by the leaky sunroofs. Combine that with long periods of non-use and the harsh environment of the roof space and the internals can seize up in extreme cases. However, with a bit of care and a good clean even the worst offenders can be brought back to life.

Sunroof motors from a D2 can be identified visually by the red plastic 'timing' disc surrounding the drive-cog (D1 motors have white discs). All the motor cases are marked with manufacturing and install dates, but that doesn't mean much when you consider even the youngest factory fitted ones are now knocking 15 yrs old!

The motor bodies are secured to the sunroof frame by three bolts. The locating holes are already present on every sunroof frame. It is important to source the mounting bolts as one is a bit unique. A good parts dealer should know this and supply the bolts with the motors. 

Timing Marks.

There is a micro-switch mounted near the edge of the red plastic disc and indents on the side of the disc control the operation of the motor as it revolves with the cogwheel. It is important to get this 'timing' correctly set before fitting the motor to ensure the sunroof will open/tilt correctly. This is easy enough to do before the motor is attached to the frame... 

Timing mark (hole) correctly positioned to side of micro-switch. This is the position the motor must be fitted to the 'closed' sunroof  frame.

There is a small drilling on the outer edge of the disc that must be aligned with the edge of the micro switch as shown in the above photo. Look closer and there will be a yellow painted mark on the metal casing as well. In the above photo it has faded badly.

This setting represents the closed and locked position of the sunroof mechanism and provided the motor was removed and refitted to the sunroof frame when the sunroof was closed and locked then all should be Ok.

If the motors are bought second-hand it's an easy visual check to do, particularly if the motor has been stripped down and re-assembled to repair a seized mechanism. 

Should the timing marks not be aligned it is simply a task of powering up the motor and letting it run its cycle till the timing marks align. An alternative method is to use an Allen key in the drive spindle recess to wind the motor around.

Seized Motors.

I sourced my sunroof motors from the Internet and when they arrived, I tried to hand operate the mechanism by gripping the cogwheel and twisting it. They would not budge and it led me to fear that they where seized. I then remembered the Allen key recess on the base of the drive spindle.

Fitting a suitable Allen key in there did shift the motor but the effort required was more then I would have expected. However, attaching a 12v supply to them soon kicked them into life. A spare 12v 45Amp car battery was used as the power source. The motors are power hungry and any current below say 15Amp might not kick them into life.  When fitted to the vehicle loom, their supply circuit runs a 30amp fuse.

At the time, I had already read up about fixing a seized motor. There are a couple of excellent illustrated tear-downs currently on the Internet and they can easily be found by a Google search for 'Discovery 2 sunroof motor'.  The post by 'Bigdave' on 'Landyzone' has an in-depth step by step photo guide....

After a strip-down and a good clean-out of the mechanism, it should return to life. Although my motors were both functioning, I decided to open them up for a peep inside. All looked OK and there was no signs of water ingress so I reckon they have had an easy life so far.

The Electric Sunroof Wiring Loom.

Research on line about the presence of the elusive loom throws up some differing opinions. Obviously it will be present if the vehicle already has electric sunroofs fitted, but it also appears that the loom was sometimes fitted even if the sunroof operation was 'manual'. This seems to be the case for the D1 and the D2. However, when the 'facelift' D2 model appeared in 2002, it seems that the loom was omitted unless the vehicle was fitted with electric sunroofs?

The loom itself is neatly self contained. One end has all the relevant connectors for the motors, switches and control box and the other end has a single plug that connects to the main vehicle harness. This modular design makes its installation easy, it also makes it's omission an easy cost-cutting measure.

Hx is a 'facelift' 2002 model D2. So the first task was to find out if it already had the loom or not...  

There are two ways to do this.

(1) - Remove the overhead console and stare into the Abyss! If present, all the connectors will be readily apparent. There will be a mixture of blue, green and white coloured connectors.. 

Overhead console removed showing the loom connectors, motor and 'magic box'.

(2) - The other option is a bit easier and involves looking for the brown 3-pin connector at the other end of the loom. The loom is routed along the top of the windscreen and down the RH A-post pillar and terminates behind the RH foot-well kick plate. 

With the kick-plate panel removed it is easy to see if the sunroof loom is present in the vehicle by looking for the fitted brown 3-pin connector....

Two photos above show the brown female 3-pin connector (C0454) located behind the RH foot-well kick-plate. This is the sunroof loom feed from the main vehicle harness. In this photo, it is unconnected which means there is no sunroof loom fitted! Count your blessings if you find this connected with the matching male brown connector (C0457) as it means the sunroof loom is already installed!

Sourcing the loom

As the loom is fairly compact and modular, it is easy enough to pop into a Jiffy bag and be posted around the world. I sourced everything I needed for the conversion from the Internet. I still feel that the best place to go, look and learn is the local breakers yards, but it can be very hit and miss... and it depends on location... And the yard. The Internet wins again.

The loom I ended up buying was from a D1. It was advertised as such and was at such a bargain price I just could not say no. Some of the connectors needed changing but it was a simple task as I already had some spare matching connectors. I would however, recommend buying a D2 loom for the conversion on any other D2!

How to tell them apart is easy. A D2 loom will have the brown 3-pin 'in-line' connector at one end as discussed above. The D1 main loom connector is much more 'blocky' and not brown coloured! The only other difference is to the connectors on the rear of the four switch control buttons which were updated on the D2.

When it came to connecting the D1 sunroof loom to the D2 main loom on Hx, I kind of hummed and arred about sourcing the proper fitting and wasted time searching the Internet for a suitable match. In the end I just removed the three spade terminals and connected them directly into the main harness plug. Some gaffer tape for insulation and Bobs your uncle!  I tell myself one day I'll source the proper connector, but out of sight is out of mind.

When it came to powering up the circuit, I had the use of a Nanocom unit to interrogate the BCU and enable the Sunroof motors to function. It would be possible to hard-wire the sunroof circuit in the footwell area but the BCU control option is just better, more designed and offers time-out functions as well.

The Control Box

LR part number  -  AMR 2128

This contains all the circuitry to operate both Sunroofs. The switches and motors are all connected to it and it too has remained unchanged throughout the D1/D2 production. It is mounted onto the roof frame roughly above where the fitted courtesy light is installed. Access is easy once the front overhead console is removed. 

It should have the fitted mounting plate attached as shown above. The two multi-pin terminal connectors are part of the wiring loom and they simply plug in to the Ecu box.

Overhead Switch Pack and Console.

The final piece of the jigsaw is the overhead control switch buttons. Fitting them properly will mean replacing the front and rear overhead consoles. This is easily done with the front console but the rear console is attached to the headlining from behind the headlining and it will need to be removed to gain access.

Also, as the headlining will need to be removed to install the rear sunroof motor and lay out the wiring loom, it makes sense to do the other jobs (ie. leak seeking) as well while the headlining is out. 

A switch pack from a D2 is shown above. Note the triangular inserts on the front and rear sunroof buttons. The button in the centre is the rear isolation control. It has a simple physical latching function that can become 'sticky' and lead to malfunctions. 

Here is the reverse of a D2 switch pack showing the distinctive in line terminal sockets. Note that not all of the available terminals are used in every connector. This gave me the option of fitting the switches with some panel illumination the same as with the door window switches on the central console. Add that to LR's thousand and one improvements! 

Front Console.

Here is an image from the web of a D2 fitted with the switch pack mounted on an electric sunroof console..

The consoles are readily available from breakers, but I winced at the prices charged for what is basically a piece of moulded plastic. 

Here is the manual console removed from Hx with the switch pack that needs to be fitted to it. I decided to modify the existing console to get the switch-pack to fit and ended up cutting the winder recess out completely as there are clearance issues once the sunroof motor is fitted above it. I ended up with a flat panel just like the designed one and I cant help wonder just what could be mounted up there onto that big flat area...

Rear Console.

A single rocker switch replaces the manual winder on the rear console. I sourced the console online and easily fitted it to the headlining while it was removed from the vehicle.

The console arrived with the courtesy lamp attached and that gave me the idea to open out the blanked off housing that is used by the rear air-con control and to fit the extra light in there. 

The smaller blanking plate below the motor switch provides direct access to the motor spindle. An Allen key can be used in the recess should the sunroof ever fail in the open position and need manually winding shut. 

Conclusions.  

With the headlining removed, installing all the components of the electric sunroof and getting the system running can easily be done on a lazy afternoon. I had already spent many more hours though in planning what to do and bench testing the components before fitting them.

All the components are still readily available second hand. The motors can still be bought new for a premium price, but with some extra work even seized motors can be brought back to life. 

Personally sourcing the components from a scrapped/donor Discovery would be the ideal way to go about this conversion as you would see at first hand how the system was laid out and installed.

Removing the headlining panel is a pain but it is essential to do the work properly and to address all those water ingress issues that can or will or already have occurred.  Resolving those issues has a whole chapter to itself!

Any problems with the operation of existing electric sunroofs will almost certainly be traced back to water ingress.