The MINI Club of Ireland

The wipers on the classic went nuts yesterday for a couple of seconds, then stopped working altogether along with the heater and rev counter. Checked the relevant fuse, cleaned the connections for the crimps - no luck. had a look at the connection on the wiper motor gave it a clean - no luck either. Had another look, traced the black wire back to some kind of panel.
Another wire comes off this to a connector. One of the wires has worn through. I'm going to tape it up but what is it and would the failure of this effect the wiper motor and the other parts that share common wiring?