OK, so I purchased a pretty damn flash Multimeter for the grand sum of $17 (from Jaycar who have them in all price ranges, thanks Tony) and set about the diagnostics. Started with the “Quick test” as advised by Georges and the Clymer manual i.e. unplugged the regulator, installed jumper wire between the D+ and DF wires. The warning light went out, so, as the manual advised, I guessed it was the regulator.
Moved on to the Regulator test (as per the Clymer manual again) i.e. unplugged B+ connector on the diode board, started the bike, revved up just off idle and measured voltage between the diode board and D+ connector on the alternator brush assembly. This should’ve shown 13.5 – 14.25 but sadly showed 11.8 – 12.2. Looks like I’m getting close to the problem. Next test was to measure voltage between D+ on diode board and ground, which gave the same result. I guessed by now, the problem was, certainly, the regulator.
Off to follow another one of Tony’s leads to get a Bosch RE55 regulator. Called to see if they had one and was quoted $55, but when I turned up to purchase, was charged $46 – Bonus! It is a 2 pin device but (thankfully!) everything is labelled – the connector on the bike and the new regulator. A little bit of tinkering with connections and rigged up a ground wire (just in case) and we were all connected and good to go.
Started the bike, checked the charge at the battery terminals at 3,000 – 4,000 rpm and straight away had 13.8 – 14.2. Fantastic sight!
I must note here that where my last post said “…I really didn't get electricity, but now I'm BEGGING to learn…” well I wasn’t actually begging to learn and it should’ve read “…but now I’m BEGINNING to learn…”. I wish I never had the problem, but thanks to this and the forum’s help I’ve learned a bit and the problem is solved!
Many thanks to you all. I’m going riding tomorrow!