When I bought my 200K, there were known issues with the central locking & dome/trunk lights.
I found two PCB tracks had burnt out through water in the works.
I added wires from the supply terminals to bridge the gaps. All OK.
There was plenty of corrosion on the pinouts of the white plug and on the black power supply plug.
This car does not have a load of whistles and bells so there are only the two terminal blocks.
Door locking now functions, but on locking the PSE will run for 20 seconds. The dome and boot lights only go out after the 5 minutes have expired but stay on if the car is driven.
If I disconnect the white plug, the dome/boot light behave as expected - On at unlocking. Off on locking, but the locking/unlocking doesn't happen. Just the lights function. Exactly the same happens if I disconnect the black plug
Does the that mean there is a bad connection to one of the pins? There are only 5 wires.
Would it help to do away with the white plug and hard-wire tails with a new multi connector to the PCB?
Any thoughts appreciated.