Electrics question

[MarkCR750]

My James Captain is 6v positive earth, (I think!), the fuse is on a lead that connects to the negative terminal on the battery, is that correct?, everything works but I guess it would in this configuration regardless but is the wiring protected with the fuse on the negative lead?

Secondly I just fitted an electrex electronic ignition kit with lighting coil, the wiring diagram they supply with the kit shows the red wire from the reg/rec going to the positive terminal of the battery and black the the negative terminal, I put a multimeter over the terminals with the engine on tickover and it reads over 6v but fluctuates rapidly, like 6.23,6.33, 6.28, 6.34, is that normal?, I have no idea re electrics as you can probably tell!

[mike the bike]

You are correct,  think of it as the juice coming out of the negative terminal,  through the fuse,  powering stuff (lights, radio, air con), and going back to the positive of the battery via the frame.

[Seamus]

As above, all the old Brits were positive earth.

[Bryanj]

Digital multimeter is far too sensitive for this application, if you used the old analogue(swinging needle) type it would average the voltage and sit steady, or to put it another way , dont fret it its working.

[Lobo]

... +1 with Mike .... as long as you don’t slip up & ground some negative wire to the frame.
Yes, the fuse will protect the conventional things, but electronic ignitions /rectifier-regulators and the like can be intolerant of wrong polarity. (the fuse won’t necessarily blow in this case as the currents relevantly small)

Regarding your ‘fluctuating’ voltage - I think perspective is needed here; you’re concerning yourself with 1/100ths of volts. Back when your James was built, a digital voltmeter would not have existed, and an analogue scale would have been “it”.....with the needle fairly static somewhere abouts the 6v region, on perhaps a 12v expanded scale.
And with that... folk would have been happy.

So, my thoughts only; personally I wouldn’t bat an eyelid at those readings.
Simon.

[MarkCR750]

Great thanks all.