alternator wiring again -sorry
Forum rules
By using this site, you agree to our rules. Please see: Terms of Use
By using this site, you agree to our rules. Please see: Terms of Use
alternator wiring again -sorry
I've been having a look today in preparation for the alternator conversion and may have found the source of my confusion about this - my wires dont correspond to any of the ones shown in any of the diagrams., I dont have any yellow wires or green/yellow wires. mine are brown/green and brown/yellow
ill post a pic
ill post a pic
- Attachments
-
- 46B09C73-AAB5-4723-B9CE-32BF28FF55F1.jpeg (2.9 MiB) Viewed 273 times
- geoberni
- Minor Maniac
- Posts: 5208
- Joined: Fri Aug 04, 2017 11:19 am
- Location: North Leicestershire
- MMOC Member: Yes
Re: alternator wiring again -sorry
What on earth are you on about?Grumpy21 wrote: ↑Sat Aug 08, 2026 8:11 pm I've been having a look today in preparation for the alternator conversion and may have found the source of my confusion about this - my wires dont correspond to any of the ones shown in any of the diagrams., I dont have any yellow wires or green/yellow wires. mine are brown/green and brown/yellow
ill post a pic
Diagrams are correct.
The diagrams show the wires as your car has..
Go back and look at it again...
N = BROWN
Basil the 1955 series II


Re: alternator wiring again -sorry
I’ve been sent numerous diagrams ( but not that one)
This is the one you sent me…
https://mgaguru.com/mgtech/electric/pics/cir_alt1.gif
Clearly shows yellow wires
This is the one you sent me…
https://mgaguru.com/mgtech/electric/pics/cir_alt1.gif
Clearly shows yellow wires
- svenedin
- Minor Legend
- Posts: 4671
- Joined: Fri Aug 29, 2014 9:27 am
- Location: Surrey
- MMOC Member: Yes
Re: alternator wiring again -sorry
NY=brown/yellow
NG-brown/green
NG-brown/green
1969 1098cc Convertible “Xavier” which I have owned since 1989.
Stephen
Stephen
- geoberni
- Minor Maniac
- Posts: 5208
- Joined: Fri Aug 04, 2017 11:19 am
- Location: North Leicestershire
- MMOC Member: Yes
Re: alternator wiring again -sorry
Grumpy21 wrote: ↑Sat Aug 08, 2026 8:49 pm I’ve been sent numerous diagrams ( but not that one)
This is the one you sent me…
https://mgaguru.com/mgtech/electric/pics/cir_alt1.gif
Clearly shows yellow wires
Wiring colours for a MGA.
Not a Morris Minor.
Intended to show the points of connection, not to accurately portray the colours.....
Expected you to have morris minor diagram before working on a significant electrical modification.....
I must admit I hadn't noticed the colour differences
Last edited by geoberni on Sat Aug 08, 2026 9:05 pm, edited 1 time in total.
Basil the 1955 series II


- svenedin
- Minor Legend
- Posts: 4671
- Joined: Fri Aug 29, 2014 9:27 am
- Location: Surrey
- MMOC Member: Yes
Re: alternator wiring again -sorry
Yellow and yellow/green were the colours used in much earlier models yes.
Stephen
1969 1098cc Convertible “Xavier” which I have owned since 1989.
Stephen
Stephen
- geoberni
- Minor Maniac
- Posts: 5208
- Joined: Fri Aug 04, 2017 11:19 am
- Location: North Leicestershire
- MMOC Member: Yes
Re: alternator wiring again -sorry
Which I knew and hadn't noticed the MGAGURU diagrams used the older colours.
The MGA was something like '55 -'62 as I recall.
Basil the 1955 series II


- Bill_qaz
- Minor Legend
- Posts: 2183
- Joined: Fri Jan 14, 2022 7:31 pm
- Location: Oxfordshire
- MMOC Member: Yes
Re: alternator wiring again -sorry
1962 regulator wires with alternator fitted Different colours for different years?
Regards Bill
Re: alternator wiring again -sorry
Must be - perhaps I’m not such an imbecile after all?
- Bill_qaz
- Minor Legend
- Posts: 2183
- Joined: Fri Jan 14, 2022 7:31 pm
- Location: Oxfordshire
- MMOC Member: Yes
Re: alternator wiring again -sorry
Yes yours has later fuse box with spade terminals.
Purple wires
Purple wires
Regards Bill
- svenedin
- Minor Legend
- Posts: 4671
- Joined: Fri Aug 29, 2014 9:27 am
- Location: Surrey
- MMOC Member: Yes
Re: alternator wiring again -sorry
Yes. Different colours for the wires according to the year. If you look in the Workshop Manual at the wiring diagrams the earlier models used yellow and yellow/green wires. Later models used brown/yellow and brown/green. The fact is though, we are talking about the two wires that go from the dynamo to the RB106 control box. One is the field wire F and the other is the dynamo output wire D. The dynamo output wire has a larger connector (because it is the wire that carries the output from the dynamo which is rated at up to 22-25 amps). It is not too difficult to differentiate the two wires regardless of the specific colour.
Stephen
Last edited by svenedin on Sun Aug 09, 2026 12:08 am, edited 1 time in total.
1969 1098cc Convertible “Xavier” which I have owned since 1989.
Stephen
Stephen
- Bill_qaz
- Minor Legend
- Posts: 2183
- Joined: Fri Jan 14, 2022 7:31 pm
- Location: Oxfordshire
- MMOC Member: Yes
Re: alternator wiring again -sorry
That was my point about years, sometimes even the manuals don't match, remember the discussion about wire colours to oil switches
Regards Bill
- svenedin
- Minor Legend
- Posts: 4671
- Joined: Fri Aug 29, 2014 9:27 am
- Location: Surrey
- MMOC Member: Yes
Re: alternator wiring again -sorry
I don't know the answer to exactly what year. You just have to find the wiring diagram closest to what you have and if it doesn't quite match, have a look at the other diagrams too. Yes I remember that discussion. Confusing and in that case that case the only way was to actually trace the wire at either end using the continuity setting of a multimeter. This is good practice to make absolutely sure. Take nothing for granted with these elderly cars.Bill_qaz wrote: ↑Sun Aug 09, 2026 12:03 amThat was my point about years, sometimes even the manuals don't match, remember the discussion about wire colours to oil switches![]()
Stephen
1969 1098cc Convertible “Xavier” which I have owned since 1989.
Stephen
Stephen
- Bill_qaz
- Minor Legend
- Posts: 2183
- Joined: Fri Jan 14, 2022 7:31 pm
- Location: Oxfordshire
- MMOC Member: Yes
Re: alternator wiring again -sorry
Yes its not me doing it. I was just trying to explain to the op why his colours were different to the diagram. Agreed you have to try to match to your build date and even then after many owners there can be diy wiringsvenedin wrote: ↑Sun Aug 09, 2026 12:11 amI don't know the answer to exactly what year. You just have to find the wiring diagram closest to what you have and if it doesn't quite match, have a look at the other diagrams too. Yes I remember that discussion. Confusing and in that case that case the only way was to actually trace the wire at either end using the continuity setting of a multimeter. This is good practice to make absolutely sure. Take nothing for granted with these elderly cars.
Stephen
Regards Bill
Re: alternator wiring again -sorry
Morning
Thanks for the advice given in both my posts on this topic. I’d just like to reiterate that my manual and the advice given consistently referred to yellow wires not brown (plus tracers). This post was an attempt to explain the source of my confusion having figured out for myself the difference.
Clearly my ability has been questioned (perhaps not too politely) and possibly with some justification. Perhaps I’ve overstretched the patience of member(s) more knowledgable than I am.
I’ll post no more on this topic and thank those who have helped
Gary
Thanks for the advice given in both my posts on this topic. I’d just like to reiterate that my manual and the advice given consistently referred to yellow wires not brown (plus tracers). This post was an attempt to explain the source of my confusion having figured out for myself the difference.
Clearly my ability has been questioned (perhaps not too politely) and possibly with some justification. Perhaps I’ve overstretched the patience of member(s) more knowledgable than I am.
I’ll post no more on this topic and thank those who have helped
Gary
- Bill_qaz
- Minor Legend
- Posts: 2183
- Joined: Fri Jan 14, 2022 7:31 pm
- Location: Oxfordshire
- MMOC Member: Yes
Re: alternator wiring again -sorry
Gary one comment shouldn't stop you posting, we all have different patience levels and its always more difficult helping over message than in reality when you can't see the whole picture.
When completed post some picture stating model and year of your car. This will help someone else in the future looking for the info.
Like I said lots of variation in wiring colours and mods. You may notice mine in the pic has an external link at the regulator, unlikely to be seen on others. It was alternator when I bought it and works, so I've never bothered tracing the wires. If it not broke don't fix it
if and when it fails I'll meter out the wiring and make my own diagram for reference.
Good luck with your conversion so you can get out in your minor
When completed post some picture stating model and year of your car. This will help someone else in the future looking for the info.
Like I said lots of variation in wiring colours and mods. You may notice mine in the pic has an external link at the regulator, unlikely to be seen on others. It was alternator when I bought it and works, so I've never bothered tracing the wires. If it not broke don't fix it
Good luck with your conversion so you can get out in your minor
Regards Bill