Magneto or Coil ignition

[alanjennings]

Just about to buy a model 31 with mag. and gen. Will see how it compares with mag. and dynamo, Nev!! At least will have a better chain case!!

[SPRIDDLER]

Never mind the electrics Alan; it's a twin so it's bound to be trouble.

[spookefoote1956]

If you went with electronic ignition wouldn't the whole argument be pointsless?

[mikeydpippin]

Been thinking about how I can keep an eye on the voltage and at the Bath and West show Paul Goff had a battery voltage digital readout.
So I,ve bought the readout and an on off switch.
As the bike is Positive earth, do I connect the readout live red wire to the negative on the battery via the switch, and the black wire direct to the positive terminal of the battery?.

[SPRIDDLER]

As the bike is Positive earth, do I connect the readout live red wire to the negative on the battery via the switch, and the black wire direct to the positive terminal of the battery?.

I would say No.
Red is always Positive, regardless of whether it goes to the frame (the so-called 'Earth') or through the wiring loom.
Switched Red should go to battery Pos and black to battery Neg.
It may have reversed connection protection so that if the digital unit is connected the wrong way it simply won't work. On the other hand it may stuff it

[JimFitz]

Been thinking about how I can keep an eye on the voltage and at the Bath and West show Paul Goff had a battery voltage digital readout.
So I,ve bought the readout and an on off switch.
As the bike is Positive earth, do I connect the readout live red wire to the negative on the battery via the switch, and the black wire direct to the positive terminal of the battery?.

Why not give Paul Goff a call - it would avoid damage if there is no reverse voltage protection.

Jim

[mikeydpippin]

Thanks Sprid and Jim,
As ever Paul very helpfull this is his reply, for anyone else that may find it usefull.



This is correct "Connect BLACK wire from display to on off switch connections and then connect to NEGATIVE on battery, and connect RED wire from display direct to earth or negative on battery".

Alternatively, if it is a coil ign. model take the black wire from the display to the live (-) side of the coil, this will switch the display on & off with the ign.

Regards
PG

[SPRIDDLER]

This is correct "Connect BLACK wire from display to on off switch connections and then connect to NEGATIVE on battery, and connect RED wire from display direct to earth or negative on battery".

That's rather confusing, as both wires (Red and Black) would/could then be connected to battery Neg.
The polarity of the frame (Earth) is irrelevant provided that you connect the display red to Pos and display Black to Neg.

[mikeydpippin]

Oh well tried but failed, connected the voltage readout to coil and earthed the other cable and it showed the battery voltage, started bike and voltage shows zero whilst engine running.
Connected both cables of display to battery same thing happens.
So not a good idea after all.
I was hoping to see the voltage to check alternators working ok, and to prevent breaking down again with flat battery.

[spookefoote1956]

Is your regulator / rectifier goosed?