Thanks for the reply
Attached to the back of the fuse box , which is in the driver's footwell.
If the rear heated window , rear wiper, fog light, intermittent wipers were working, then the unit is ok, but I need the beige one, not the black one.
The beige one is on later discos 1, from around '96 on, in fact from vin va534104, you can get the number from your v5