OK, After reading most of the available info for the LCM and actually removing it from the car I want to post two things:
1. Question on the transistor switch/
2. How I removed the LCM.
Here we go:
1. Question: Does anyone have idea where to buy the BST425L1? If not does anyone know if BST426L1 can be used instead (the difference I see from the googled datasheets is that the current limitation for the first is 17A and for the second 16A)? I found a source for about 3.5 pounds a piece. Also there is a source for the BTS425L1 at 3.37 but minimum of 10 pcs to purchase and 8 pounds delivery.
2.How I removed the LCM. I have:
1. Disconnected the battery, both terminals;
2. Removed the boot opening lever on the right side, next to the gas pedal. normal cross screw.
3. Disconnected the panel under the wheel. Couple of torx screws, plastic clips and I am not sure about the cross screws.
4. Removed the wood trim on the right hand side of the ignition, then the corner plastic mould. To remove the latter , there is a leather coloured cap on the right hand side and there is a screw underneath.
5. Removed the boot lid opening mechanism, two screws
6. Pulled some foam and saw bunches of cable, the bottom bit of the LCM and no way to take it out.
7. There was 4 boxes like relays in two pairs. First (closer) was kinda bluish is colour, the other pair was white. they are connected to a kind of small console by means of plastic rectangular bit. to remove you have to grasp the boxes and rotate so the rectangle bit coincides with the hole. then just dropped it to a side without disconnecting.
8. The three groups of cables going into the LCM were clipped by zip tie that was threaded through a plastic clip fixed to the body. Without getting the cables out of way I could not get access to the securing nut of the LCM> so I cut the zip tie. With cable out of way one can relatively easy undo the LCM securing nut (No.8).
9. To disconnect the connectors:
The white and black connectors at both ends of the LCM are the same. press the plastic clip and then slide the outer part to extract the connector;
On the middle one (black with white lever) rotate the lever and that will extract the connector.
Now to follow up is the LCM (HW:0 SW:31) dis assembly:
1. First I have undone the visible plastic clips and removed the rounded cover.
2. Undone the small retaining slips on each connector
3. undone the small internal clips of the bottom plastic box and slid the circuit board out.
4. Nex twas the radiator: I have undone the securing screws. Then remove the steel springs. As they are cut in three sections, I have used a small precision screwdriver to span all three parts and then used a Then you have to flex ALL components away from the contact zone but be carefull no to damage the insulation/isolation strip(s). Then the Heatsink can be removed.
5. As I have an issue with the Right high beam I have checked in my Bentley manual that this is fed through connector a/13. That supposedly is the black only connector. The other switch that supposedly controls the left light appears to be fed from the white connector from pin 6. Which confirms it after reference from the manual. At this point I think the black controls the right set of lights and the white connector controls the left lights. If I have time I will check against the mapping in the Haynes manual.
At this stage I plan to try and check the LCM tomorow to establish if the switch is gone. I plan to do the following:
1. connect the LCM - all three connectors without closing the box, but definetely with the heat sink and the clips on.
2. reconnect the battery, the right main beam should come on
3. test the voltage of the left and right switch. there should be no voltage at leg 5 of the component on the left and full voltage on the right component. but is that needed? Or just order the transistor and resolder?
I have made some photos so may be I will put the above into a single pdf.