Right - an hour in the garage and this is where I am now:
- Regulator is aftermarket podtronics jobby. I just left it alone and didn't try to work out how to test it in line with Haynes instructions.
- Bike is fitted with a voltmeter but it's always just gone bananas as soon as the engine is turning over at any revs - I thought that was just a problem with the voltmeter I.e. it's no different to my speedo which also just goes bananas and is of little use. I'm now forming a different view.
- Multimeter across the battery terminals shows this:
(a) At rest, no engine on, gives 6.25 volts, dropping to about 5.9volts once everything is on (headlamp, rear brake light, indicators). that seems fine to me i.e. my indicators are working the way they're meant to. I'm going to say they're fine and the blown fuses are caused by something else.
Voltmeter on the bike also shows a small shift to 'negative' once everything is on as above, so also suggests voltmeter actually works fine.
(b) Engine turning over at a little higher than tickover: something like 7.8v - regardless of what electrical things I turn on - so far so good. HOWEVER - every so often the reading is some strange number, almost random, bouncing around into the teens. It's like it's intermittently switching from 7.8v to a random series of other numbers, but always coming back to 7.8vish as an average.
Voltmeter just goes bananas and is useless, as soon as engine is turning.
(c) Engine running at tickover: multimeter gives even weirder readings: virtually no readings that seem 'about right' - all strange numbers in the high teens, then low, then just all over the place. Really weird.
(d) Engine given some revs: voltmeter goes completely mental - bounces around all over the place. I haven't found a way to use the multimeter while revving yet (bit pushed for time). Will check later but my suspicion is the readings would be 'all over the place'.
From this my diagnosis is:
- There is probably something wrong with my regulator and I'm just going to replace it. Costs £30 - dead easy to replace - worth a shot.
- My indicators are probably fine, but what's happening is that regulator is not doing its job properly and this is causing fuses to get blown in my indicator circuit (which is its own circuit - with its own fuse).
- my voltmeter is also fine and is simply trying to display the 'all over the place' nature of my dynamos effect on my battery.
Thoughts always appreciated!
Cheers
Sam