Td5 D2 Seats - Electric Seat Controls

ELECTRIC SEAT CONTROLS. 

Another recent E-bay find was a pair of electric seat controls c/w their wiring looms. Their purchase is a significant step for the project and attention now turns to sourcing the new seats...

There is a thriving second hand market in these components and they are all readily available online with some of the components still available 'new'. 

They still command good prices with the above set of loom, switch pack and mount plate/switches easily going for over £100 if bought separately. Just one of the switch packs is available new for around £80.

I managed to buy two complete looms for a bargain £35 aided by the timely arrival of a discount voucher from E-bay.

Accurately described as 'used' and in need of a clean there was also also an issue with a 'sticky but functioning' drivers lumbar control switch.

I took a gamble on being able to strip it down and clean it up to return it to a  fully functioning condition. 

First job was to investigate the 'sticky' lumbar control button shown on the right of the above photo. All of the control stalks are spring loaded to ensure that once released the switch 'button' returns to its neutral position.

A close-up of the affected switch button in position on its faceplate. Clearly visible is a dribbled residue below the button. When I first saw this I knew it was the reason why the switch was 'sticky'. I hoped it was some sort of spilled sugary liquid, but was also mindful that it could be residue from a burnt out electrical contact... When I removed the affected button, the spring return on the switch stalk worked fine pointing to an issue with the button itself.

This is a close up showing the gunged-up reverse of the affected lumbar button. The two 'sockets' locate onto the switch-pack stalks and the lower one here was causing the problem by overcoming the return-spring tension inside the switch pack..  The solution was a good clean and scrape out of the gunge and then the problem just went away...

Two photos of the front face of the switch-pack minus the mounting plate. The first shot shows the corresponding switch buttons.

All the fluff and debris was quickly cleaned away to reveal the springs in the stalk apertures. A drop of oil was applied to lubricate the mechanisms.

Worthy of note is the 'BMW' logo on the yellow label. Makes me wonder if this component is from the BMW parts bin.?  The '61.31..' number is a BMW parts number and a quick search online finds the same unit fitted throughout the BMW range from the early 90's onwards.

Another point to note... The hollow tubular switch stalks are missing their sprung (?) metal 'caps' ( which can be seen on photos of the new units, - see below.). They probably flew-off during the dismantling. 

They don't effect the function of the switches but they must be there for a reason. Perhaps its just to improve the 'feel' of the control, but I fancy that their real function may be to mount an LED bulb for internal illumination of the switch. I will have to research this and delve into the various BMW applications.

Well, having looked around the web, the idea of fitting panel lights is fading away.. I could  not find any direct reference to lights fitted onto the switch stalks on these BMW switch packs. But that's not to say it's impossible! The biggest hurdle will be in getting the button graphics to be translucent in order to allow the light to shine through.

Managed to download a photo of a BMW switch pack 'opened up'..

That just about satisfies my curiosity! A common problem is that the black plastic 'stalks' of the switch operating levers can break in two, or the small ball bearing rollers can become dislodged all leading to the above scenario.

This is a photo of the reverse of the mounted switch pack and it's corresponding loom connector. The loom connection is a clever sliding 'bayonet' type affair shown in the open position above and is a credit to its German design!

There are 12 pins on the back of the pack and all are numbered. The relevant Rave circuit diagram gives function paths for them all. Briefly, the 12v supply enters via Pin 5 for distribution via the 'closed' switch pins. There is a common earth Pin 6 connecting all the 'open' switch terminals. 

I think it would be possible to connect an LED across these two pins so that it would illuminate when power was present at Pin 5. Much the same as the window switches illuminate on ignition...

A close-up view of the switch-pack loom connector. The clever 'bayonet' slider is shown in its fitted position.

The pattern made by the sockets kind of reminds me of ancient writing or some sort of 'machine code'....

Curiosity gets the better of me and I took a look inside the casing, a neat hinged case affair. The red wire was causing some bulging of the case due to it being routed wrongly.

Each of the wiring looms is 'sided' and will only fit either the passenger or driver side. They are not interchangeable.

The grey multi-connects on each loom are physically different even though they each have 12 wires and perform the same functions. These female connectors are routed to the underneath of the seats where they connect to each individual frame mounted seat loom.

RH Seat  -  YML 100300 

LH Seat -  YML 100310 

Not shown on the above photos but also written on the labels is a test date..

RH   -  Fri  17-11-00 @ 09.49

LH  -  The  21-11-00 @ 08.55

That would make them older then the big fella itself..!!

MOUNTING THE SWITCH - PACK TO THE CONSOLE. 

The design of the switch-pack may well be German but the mounting method is a good old LR 'that'll do' affair. The switch pack is held onto the mounting plate by four thin flimsy plastic tabs that are just not up to the job and, in the case of the right-hand mounting plate, only one of the four now remain!..

On the centre right is the single remaining hooked switch-pack retaining tab.

Another view of the back of the mounting plate showing the same tab in the six o'clock position. The 12, 3 and 9 o'clock mounting tabs are missing.. As are a couple of 'locating' tabs at the top left.

What's particular galling, is the fact that the German designed switch pack still retains its four sturdy metal mounting 'springs' which remain unused for the LR install.

Two views of the unused metal mount spring plates. The last view shows another mount tab clinging on for its life in between those metal springs...!! 

Because of the lack of usable mounting tabs I will have to come up with some method of securing the switch-pack to the back of the mounting plate.

Knowing that the switch-pack is from the BMW parts bin, I decided to do some research online to see how it was mounted onto cars in the BMW range....

The two drilled holes in the top-plate either side of the hollow control stalk are used on BMW installs to locate counter-sunk mounting screws that secure the switch pack to its mounting plate. The visible heads of the screws are shielded from view by the switch button and it's something I would like to try.

A search is on for suitable screw heads before I commit to some drilling!

This image shows the mounted position of the electric seat switches on the centre console facing the Left-hand seat. The mounting plate simply pushes into a pre-cut hole and is retained by plastic lugs.

The above photo shows a new 'auto' centre console with the cut-out mounts for the electric seat controls on the side of the cubby box. Note also the leather trimmed lid on the cubby box.

Here is a photo of a 'manual' console complete with the seat control cut-out on the side of the cubby box.

The manual console in Hx lacks the pre-cut mount-holes for the seat controls and will either have to be replaced or have the holes fabricated. 

Second-hand prices for what is basically some shaped plastic put me off buying a centre console with the pre-cut cut-outs and I fancy having a go cutting out the holes in situ myself....    what could possibly go wrong...? 

MODIFYING THE CENTRE CONSOLE 

Started off by making a card template in the shape of the hole that needs to be cut into the side of the console....

Needed to get a nice tight fit around the contact points on the rear of the mount plate. After some modification, I arrived at the above and after tracing out the outline shape of the front face of the switch mount plate, I ended up with the paper template shown below...

This photo shows the Right-hand mount plate and drawn onto the paper template above it is the area to be cut-out of the console side. The paper template can be reversed to mark out the other side of the console. 

Also visible on the mount plate are two pencil dots that represent the holes to be drilled through the mount plate in order to better secure the switch-pack to the reverse of the mount plate.

Here is one of the templates taped in position. I was using this opportunity just to check it was feasible to do the work without removing the console...  (or the seat!).

The central window-switch panel can easily be removed for access, but the innards of the Cubby-box itself are pernemently attached to the centre console.

This does restrict the access behind the console panels, but it is still possible to look inside and get fingers in there to make sure everything is clear before the cutting commences.

I wanted to check that the insides of the centre-console side panels were not already 'pre-scored' with the outline for the fitted switch panel. I figured that as the console is a universal fitting on every Discovery, the moulding may have the locations for the switch panels, but not in this case. 

So it was back to final placement and the marking out for the cutting.. I thought of placing the switch panel higher up on the side of the Cubby-box, but realised that the clearance behind for the switch pack and the cubby box sides means that's not possible (?)

I modified the template a bit more by cutting out little triangular pointers that mark out the contact points for the switch plate. I then marked each point with a sharp pointed file and then joined the dots with a pencil to get the guide line for cutting..

Decided to use a cutting disc on the end of a flexible extension to a 'Dremmel' type tool. The disc easily sliced through the plastic panel, but I also made use of a craft knife to finish the cut.

tbc...