HELP - Endura Fiesta mkiv alternator problem

Hi, I have a couple of Fiesta Mk IV's, one a 97 1.25 Zetec, the other a 2000 Endura E which is reg June 2000 and VIN code date May 2000 which places mine after the Feb 2000 spec changes and many wiring changes incl alternator.

My Endura stopped charging, only a few millivolts across ground and alternator outputpost, I renewed battery in case dead cell, still no charge. I replaced alternator with new, still no charge, no output from alternator, tried another alternator, same result.

Then I noticed that no alternator light was showing on dash console. I checked wiring harness from alternator. By clutch housing the alternator bu/bk and wh/bu wires branch out into a 2 pin plug which is not connected to anything. A long search found no socket for it to plug into.

Endura wiring diag for post Feb 2000 shows the bu/bk wire connecting to pin b1 of the 'multi-function electronic module' (is that what Ford call the ECU). So that 2 pin plug must connect somewhere.

Please can someone let me know. I searched for over an hour all around engine, from underneath and followed all wires into engine bay. The plug is clean so it must have been in a socket.

Regards Jonathan