C15 charging system

[TTJOHN]

I have just replaced the old stator on the C15 as it was not charging, now I have replaced it with a two wire stator 12v, I have connected it up and after some faffing about with the wiring to try and get it correct. I have the lighting circuit, also ignition, the bike runs but it does not show any charge on the ammeter, the ammeter appears to be working correctly and shows, as it should the opening and closing of points when starting the bike. I did check the A/C from the stator that was okay, i's a new relay regulator in the circuit, the D/C at the battery is very low from the stator. I did wonder whether the battery was at fault.
Any idea's from the knowledgeable out there, please.

[JulianS]

Are you using the correct 74mm diameter rotor with the new stator?

Earlier alternators used a 70mm rotor which wont work properly with the later stator.

[rhyatt]

If you have a voltmeter, put across the battery directly.
Standing doing nothing ign off should be about 12.5.
Rising to around 14.2 after a while running.
This will show if the battery is being charged.
You don't indicate if you have a regulator/rectifier fitted ot just a plain , pure rectifier.

[TTJOHN]

Hi Rhyatt.

I have a new relay rectifier  from Goff but as Julian pointed out, I must check the width of the rotor to make sure its 74mm, I'll let you know my findings later. Thanks for the advice Julian & Rhyatt.

[rhyatt]

Don't  forget to fully charge the battery before t
You do the voltmeter checks

[TTJOHN]

Rotor is correct size, I am using a dry cell battery and using my Avo meter across the battery when running only shows movement of about 2volts when running and revving but still nothing on the ammeter.

[rhyatt]

a dry cell battery is incompatible with charging
only a lead acid type of battery will accept AC recyified/regulated to DC

you should start from about 6.4 or 5 V (or 12.5 v) then revving not a lot will/should  bring it up progressively to around 14V or 7.2V

but ensure that the battery is fully charged before doing these tests

the ammeter side of things can be resolved by wiring reworking

basically - the battery supplies everything THROUGH the ammeter and will receive its charge THROUGH the ammeter - this wil then let you know by virtue of the + and _ readings what is going on with the battery

most/if not all motorcycle 6v or 12 v systems prefer a lead acid or sealed type and probably not less that 5 or 8 Ah capacity

[TTJOHN]

Rhyatt.

I got mixed up, I do actually have a correct battery on this one, just checked with Avo meter and its a good a/c charge coming from the alternator, so that is going into the relay regulator, which is new from Goffy but I don't seem to be getting any d/c from the relay regulator, and nothing showing at the battery.

John

[rhyatt]

Ok,
You have good AC coming from the alternator into the regulator/rectifier.
Why not momentarily, disconnect the 2 output wires from the reg rec into the bike and rig up 2 totally separate wires from the reg rec to the battery?
Take care on polarity of course.
Then run the bike and see what charge is going into the battery then.
Ball park figures 12.5 volts sitting nothing turned on
Something around 13.9 or 14v when running at a reasonable engine speed, not screaming   but say 40mph engine speed.

This will prove your alternator and reg rec and battery charging.

Leaving you to resolve the ammeter wiring

[TTJOHN]

Rhyatt.

I will try that on  I get a chance,  I am just getting ready to go to Long Compton for the members meet. I'll let you know what happens after I try .

Cheers John

[TTJOHN]

Rhyatt.

Well I did what you suggested and it has a good healthy charge, all I have to do now is trace the wiring to see where the fault lies.
Thanks for your advise. John.

[rhyatt]

Well done.
At least you know the prime components are working well