found the problem ...

 ... but not fixed it!

I eventually worked out which of the connectors was causing the fault with the headlight. Well at least I hope I did. I tried taking it apart and connected it up without the connector body and it worked. Then it didn't! Rebuilding the connector didn't seem to help any so I've ordered a new Deutsch connector and will fit that.

The wiring is getting so bitty, I really should rewire the bike completely next winter. If I do I'll replace all the connectors with appropriate Deutsch ones. They are much easier to work with than the AMP multi-lock which Harley also use. God knows why they used a mixture on the one bike. Cost no doubt.

After things had come to a halt with the wiring, I decided to adapt the seat bracket. I sawed off the seat posts which were angled to take the Harley specific springs which sit at an angle. I then drilled and tapped new holes to take the spring mounting bolts. It's all together but I've decided that I want to use a deeper bolt for security so will buy a helicoil kit and use inserts. That will save me from having to use my tap set which, being a cheepo, was extremely difficult to use as the handle for the taps kept slipping and I eventually had to improvise with a 1/4" ratchet handle. 

See buying cheap tools! It's never a good idea.