wanted, upper speedo cable for mk1 XM

[xmexclusive]

The using the black display with a Mk1 drive board keeps everthing electrical Mk1 except the speedo.
Warning lights are correct.

Anything you can check out and confirm please do and record here.
It will make the project a bit more complete and documented.

John

[citroenxm]

First issue id the Speedo electric board wont fit the Mk.1 moulding... however, if the rear was to be cut away, there is also PCD provision and space so that can be cut back to allow it to fit into the Mk.1 Board..

The handy thing is as there is no Mk.1 Tracks to take the speedo, theres only three wires, so Im sure added soldered wires can be easyilly done providing Mk.1 Pins are vacant to where they need to go, although that can be anywhere if its not on the PCB.

[citroenxm]

Looking at the Mk.1 mould John, there is only TWO openings I think it needs to fit...

Open by making a SLOT in the TOP section so the PCB can slot in upwards, and make another hole in the side where the Plug connector goes..

Thats all it needs


Side section needs taking out here for the plug to fit through..


A section needs cutting out here too for the PCB to protrude out slightly aswell and bobs your uncle its in with the correct black face!

[citroenxm]

The existing cog should be fine.
The drive boxes normally come without cog and as you say are common across many PSA cars.
I bought a 2.5 one from a Citroen dealer many years ago and it came in a packet marked for the Saxo.

I will check the top end pcb's and components today.
Early and late Mk2 speedo's have different warning light prints and Mk1's may have even further variations.

Have now completed a check on the differences between Mk1 and Mk2 displays.
I then stripped them taking record photos.
The Mk1 was an Auto display and the Mk2 from a manual.
The good news is that the three speedo feed wires go right to the speedo head still numbered 1, 2 & 3 on the pcb.

I then set about working out what was involved in swapping the mechanical speedo for an electric one.
First problem noticed was Grey (Mk2) dials and Black (Mk1) dials.
There were many differences on the pcb wiring and display light designations so I decided complete assembly swapping was not for purists.
How many of you will be happy with grey dials in a Mk1.
The other big stumbling block was the white plastic display frames.
The Mk1 one did not have a large enough hole for the electric speedo.
So I decided to fit the Mk1 dials in a Mk2 frame.
That lets me use the two outer displays which swap and fit perfectly in the Mk2 frame.
I just needed to swap the speedo front faces, which threw up a few more problems.
The Mk1 speedo has two little black headed screws either side of the speed needle centre so easy to get that faceplate off.
The Mk 2 speedo display was different with the screws put in before the faceplate was glued on.
When you reassemble you need to use the Mk1 clear plastic light bar as the Mk1 one does not fit.
Inset the mileometer reset push and now there is the problem of getting the speedo needle refitted correctly.
Not done that yet, will make some notes if I take another one to bits.
Now I needed to fit the Mk1 pcb to the back of the White frame but the central hole is too small for the speedo bump.
Also the 3 speedo wires need adding.
Marked out the pcb ready to enlarge the speedo hole but this may cut some of the tracks.

To be continued.

John

John, this can be changed a bit now I found that if you remove the Mk.2 speedo face plate which is stuck on under it is the screws etc in identical places to swap the Mk.1 face onto the Mk.2 drive unit. Light bars are identical on both units.

As discussed above theres no need to touch the Mk.1 PCB, slots in the Mk.1 speedo protrustion house can be made so the PCB edges can sit correctly as Ive tried to exaplain.

[citroenxm]

The only additional wire needed is speed signal direct from the speed sensor adding.

The speedo gets its earth and feed from slightly improved tracks (size wise for the slightly higher current) on the PCB. Both earth and power feed are sourced on the PCB.

Signal feed comes on on Pin 1 on the red connector (Left side of it looking at it directly)..

On Mk.1 PCBs this pin appears Vacant and has no tracks going to it, so with a bit of small wire and a soldering wire is easilly added. The rest is getting the signal cable from the gearbox sensor into the car.

[JD01JD]

I remember a year or so ago coming across a flickr album of someone converting an S1 speedo to the S2 electronic one. Sadly I cannot find it now however I did find a youtube video with the photos in it:

[youtube]6qSBnedmCe0[/youtube]

For the speed signal it looks like they ran a wire to an unused pin on the blue connector from the bitron speed converter / amplifier box (up in the drivers footwell).

Jordan.

[citroenxm]

Ahh haa.. now thats an interesting find, certainly to NOT need to add a speed sensor in the gearbox..

Taking from the Black box is a bit easyer... Damm good find there!!!

This topic will be split to make a proper Conversion topic now...

The signal can be picked up from any vacent pin, in reaility it doesnt need to go to a pic at all, but it makes it easyer for removal.

I note there cutting of the White section for the PCB to fit was a bit more drastic, I dont think the whole rear needs to come away, it only needs holes making opposite the offending parts, top of the PCB and where the plug goes to connect to the speedo..

[Dieselman]

Has anyone got any spare S2 speedo's? I find the wobbly needle a bit annoying.

[citroenxm]

Ill need to see how many I have and how many I need.. one for my 24v .. one for yog v6 12v .. one for the 2.1td auto also..

[xmexclusive]

There is another difference that I have just noticed.

The Mk2 speedo face plate with the speed markings has a black needle stop at the 5mph mark.
It seems that on my trial version I lost this needle stop while attempting to peel the grey face plate.
The Mk1 speedo face plate lacks any needle stop.

The Rev counters and the oil/ temp/fuel displays (Mk1 and Mk2) are all electrical and have physical movement stops built in.

I think this needs checking out in case it is critical to correct operation.

John