While doing another job in the trunk of my 1990 740 I noticed the black box arrowed in the picture below.

From the wiring colors connected it is in the speedo sensor circuit.

I just wondered what it contained, (seems rather big for just a connector) any ideas?

Second question,
I have just built a variable delay unit for the wipers and I`m now trying to figure out how to connect it into the wiper circuit.
The delay unit has it`s own on/off switch and a relay which closes mometarily after the preset delay to trigger a single sweep of the wipers. The relay contacts could be in a positive or negative line.

Has any one figured out precisely how the wiper switch, relay and motor interact or has the information in a better manual than my Haynes.
Any ideas greatly appreciated,

Colin.

1990 740SE B200E/M47, remote C/Locking.