RJD393
Well-Known Member
First - the muppetry. I had forgotten the basic rules of tracing a wire - 'make sure it is not connected to anything else at either end before checking continuity'!! It was much easier to see once I removed the alternator. The wire that I thought was from D+to the service battery was actually connected to the yellow wire from the alternator so was disconnected and the yellow wire reconnected to the spade terminal on B+. I guess the other connection was some form of external regulation/sensing but now the wiring makes sense and works! Thanks to all who commented on my previous post.