battery not charging
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NickTatlow
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- Joined: Sat Dec 21, 2024 9:22 pm
- Location: Staffs UK
Re: battery not charging
Thanks, will try.
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Groily
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- Joined: Thu Jul 04, 2002 1:00 am
- Location: NORMANDIE FRANCE
Re: battery not charging
As g80csp11 says - but just in case you're on a hunt for the wrong thing - there can never be anything showing on the ammeter when the battery is disconnected.
If the engine stays running and the lights work with varying brightness that's rev-related with the battery disconnected, that's a Very Good Thing as it shows the alternator, or parts of it anyway, are working. But without the battery, they are being supplied without the current passing through the ammeter.
Reference your wire hunt:
You should, if your machine is 'as Lucas intended' have a 3 wire RM19 alternator. By 1963 the three wires off it were almost certainly White and Green (common to all the coils, three pairs of), Green and Yellow (the other end of 2 pairs of coils - the powerful set) and Green and Black (the other end of just one pair - lower power for when headlamp is Off). See pages 75 and 76:
https://archives.jampot.dk/book/Owners_ ... Manual.pdf
And see page 86 for what wires go where so you can identify them:
From the alternator:
Green and Yellow goes to the Ign Switch terminal 17.
White and Green and Green and Black both go to the rectifier.
From the rectifier:
White and Green then goes on to Lighting Switch terminal 4
Green and Black goes on to Lighting Switch terminal 7
There's a wire to earth, probably Red.
And then there's the main highway that provides rectified, DC, current to the ammeter and thence to the battery - that would have been a Brown and White wire.
If you've still got the original type of switches, the terminals that are connected to each other in every switch position of both, is also shown on p86.
Chances are that the switches are OK but those are useful graphics.
Chances are also, from what you say, that the alternator works.
Chances are probably lower that the rectifier is working, which you are pursuing.
Query any duff wiring connections or broken wires . . . also on your agenda.
Here's hoping, then, that the replacement of the rectifier and checks over the associated wiring does the trick. Good Luck!
If the engine stays running and the lights work with varying brightness that's rev-related with the battery disconnected, that's a Very Good Thing as it shows the alternator, or parts of it anyway, are working. But without the battery, they are being supplied without the current passing through the ammeter.
Reference your wire hunt:
You should, if your machine is 'as Lucas intended' have a 3 wire RM19 alternator. By 1963 the three wires off it were almost certainly White and Green (common to all the coils, three pairs of), Green and Yellow (the other end of 2 pairs of coils - the powerful set) and Green and Black (the other end of just one pair - lower power for when headlamp is Off). See pages 75 and 76:
https://archives.jampot.dk/book/Owners_ ... Manual.pdf
And see page 86 for what wires go where so you can identify them:
From the alternator:
Green and Yellow goes to the Ign Switch terminal 17.
White and Green and Green and Black both go to the rectifier.
From the rectifier:
White and Green then goes on to Lighting Switch terminal 4
Green and Black goes on to Lighting Switch terminal 7
There's a wire to earth, probably Red.
And then there's the main highway that provides rectified, DC, current to the ammeter and thence to the battery - that would have been a Brown and White wire.
If you've still got the original type of switches, the terminals that are connected to each other in every switch position of both, is also shown on p86.
Chances are that the switches are OK but those are useful graphics.
Chances are also, from what you say, that the alternator works.
Chances are probably lower that the rectifier is working, which you are pursuing.
Query any duff wiring connections or broken wires . . . also on your agenda.
Here's hoping, then, that the replacement of the rectifier and checks over the associated wiring does the trick. Good Luck!
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NickTatlow
- Member
- Posts: 10
- Joined: Sat Dec 21, 2024 9:22 pm
- Location: Staffs UK
Re: battery not charging
Tested old rectifier with multimeter and looks like it's not working. Next challenge is to connect new solid state rectifier. Old one has three wires into unmarked rectifier spade connectors. Offside green and white (double), middle brown and white (single) and nearside green and black (double). The colours don't correspond with the ones on the wiring diagram that came with the bike (of course). New rectifier has positive, negative and two A/C connectors. On the diagram it looks like alternator to rectifier is the nearside terminal, battery to rectifier is middle one, via ignition switch and offside to lighting switch. Any advice as to which wires go where? Should it be alternator to A/C terminal, earth to positive and battery to negative?
Beginning to wish they'd taught me something useful at school.
Beginning to wish they'd taught me something useful at school.
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Groily
- Member
- Posts: 2368
- Joined: Thu Jul 04, 2002 1:00 am
- Location: NORMANDIE FRANCE
Re: battery not charging
Sounds as if what you have is exactly what you should have. The colours are as per my previous comment, and more to the point, per the Owners' Manual!.
Brown and White off the middle is the rectified DC feed which is the main supply to ammeter, switches and battery.
The old rectifier was earthed by the mounting stud, so no separate wire for that - but you'll now need one.
Both GB and GW are double because the wires from the alternator arrive at the rectifier and then then go off to the lighting switch exactly as per the wiring diagrams on the pages of the relevant book to which I referred.
Ignore whatever wiring diagram 'came with the bike' - there were various colours used by Lucas over the years, and also a few minor differences in configuration. All very similar, but the late RM19 alternator such as you have will use the colours you have got, and the diagrams in the Owners' Manual are absolutely correct unless you are fitting a combined rectifier / regulator (which you aren't).
(The other wire from the alternator, GY, will go to the ignition switch as also described.)
With the new rectifier, with 4 terminals - you've got it spot on. There should be markings on opposite corners that look like an 'S' on its side for the alternator AC wires, doesn't matter which way round. The Brown and White, which is the DC output, goes to Negative, and a separate earth is now required, from Positive. (Assuming you are staying positive earth that is.)
If the Gods are with you and the fault was at the rectifier, you should see normal service restored with the new one hooked up.
I'd still check that the wires on the switches are on the terminals the Book says they should be on, in case the PO tried to get round the faults you are grappling with by making unsolicited changes. It happens!
Brown and White off the middle is the rectified DC feed which is the main supply to ammeter, switches and battery.
The old rectifier was earthed by the mounting stud, so no separate wire for that - but you'll now need one.
Both GB and GW are double because the wires from the alternator arrive at the rectifier and then then go off to the lighting switch exactly as per the wiring diagrams on the pages of the relevant book to which I referred.
Ignore whatever wiring diagram 'came with the bike' - there were various colours used by Lucas over the years, and also a few minor differences in configuration. All very similar, but the late RM19 alternator such as you have will use the colours you have got, and the diagrams in the Owners' Manual are absolutely correct unless you are fitting a combined rectifier / regulator (which you aren't).
(The other wire from the alternator, GY, will go to the ignition switch as also described.)
With the new rectifier, with 4 terminals - you've got it spot on. There should be markings on opposite corners that look like an 'S' on its side for the alternator AC wires, doesn't matter which way round. The Brown and White, which is the DC output, goes to Negative, and a separate earth is now required, from Positive. (Assuming you are staying positive earth that is.)
If the Gods are with you and the fault was at the rectifier, you should see normal service restored with the new one hooked up.
I'd still check that the wires on the switches are on the terminals the Book says they should be on, in case the PO tried to get round the faults you are grappling with by making unsolicited changes. It happens!