250 Model 14 alternator Wipac to Lucas

Information relating to the Matchless G2 or AJS Model 14 250cc Lightweight
Locked
Renegade2018
Posts: 4
Joined: Mon Sep 30, 2019 4:17 pm
Location: Hampshire

250 Model 14 alternator Wipac to Lucas

Post by Renegade2018 »

Hi all...

New member with a question...
I have in my garage a 250 model 14 with a dead Wipac alternator, i was advised to replace it with a new Lucas RM19 stator and rotor and fit a solid state rectifier and have now done so.
Problem is i cant seem to get the wiring right !
Can anyone plese help me with this problem.

The wiring harness to the alternator has White, Orange and light green to the origanal alternator
The new Lucas RM16 has Green with yellow stripe, White with Green stripe and Green withBlack stripe..

There must be some way to wire this all up and get it charging correctly but i dont know how.

Any help or advise would be greatly appreciated

Many thanks...
User avatar
Janet
Member
Posts: 4147
Joined: Mon Jan 01, 1996 12:00 am
Location: EAST YORKSHIRE UK

Re: 250 Model 14 alternator Wipac to Lucas

Post by Janet »

Green/white >>>>>>>>> white
Green/yellow >>>>>>>> green
Green/black>>>>>>>>> orange
Image
Renegade2018
Posts: 4
Joined: Mon Sep 30, 2019 4:17 pm
Location: Hampshire

Re: 250 Model 14 alternator Wipac to Lucas

Post by Renegade2018 »

Hi Janet..

Thank you for you reply and helpp with this, i will try again tomorrow with this colour change over, although i think this is what i origanally thought myself
I double check and let you know how i get on..

Is this something you hade done before of this bike ? i was looking for a new Wipac but couldnt find one, however this conversion was recommended to me but i dont know of anyone who has actually done it..
And since i have done it i have had other people say it wont work.

although i cant see why not !

all very confusing lol..

Many thanks

Steve...
Paul R
Posts: 43
Joined: Sat Sep 09, 2017 6:04 pm
Location: west yorks UK

Re: 250 Model 14 alternator Wipac to Lucas

Post by Paul R »

I've done this conversion on my M14 , If you join the Green/black wire and the green/yellow wires together then you are in effect making a 2 wire alternator . These 2 wires go to opposite " corners " of the solid state rectifier . The other 2 connections on the rectifier are then feed to battery negative and the other to an earth point . This will give you 12 volts however you will need to wire in a zener diode on a heat sink as fitted to older triumphs BSAs etc to the battery to avoid overcharging . If you are looking at retaining 6 volts then there are usually 6 coils in the lucas stator split 4 and 2 . There are some diagramatics on the web which show the lucas wire coding for this I seem to remember, but it then gets quite a bit more complicated which is why i went for the 12 v option . Hope this helps a bit anyhow .
User avatar
Janet
Member
Posts: 4147
Joined: Mon Jan 01, 1996 12:00 am
Location: EAST YORKSHIRE UK

Re: 250 Model 14 alternator Wipac to Lucas

Post by Janet »

Renegade2018 wrote:Is this something you hade done before of this bike ? i was looking for a new Wipac but couldnt find one, however this conversion was recommended to me but i dont know of anyone who has actually done it..
And since i have done it i have had other people say it wont work.
I was told that, too but since I had a damaged alternator (working but with some dodgy wires on at least one coil ) I looked for a replacement. The Lucas one has been been on the bike since 2011 when I melted my electrics. :oops:

As Paul said, the Lucas coils are split 2 pairs and 1 pair not the 3 and 3 configuration of the Wipac. If you're keeping to 6v it is important where you connect these in the right place as the single pair covers the general running plus pilot and tail lights. With the headlights on, all the coils are connected to give full power. On the Wipac, I believe the two sets of 3 are interchangeable.

Edited bit in red to correct '2' to '1'.
Last edited by Janet on Wed Oct 02, 2019 12:24 pm, edited 1 time in total.
Image
Renegade2018
Posts: 4
Joined: Mon Sep 30, 2019 4:17 pm
Location: Hampshire

Re: 250 Model 14 alternator Wipac to Lucas

Post by Renegade2018 »

Hi Again Janet, Paul....

Thanks again for your help..

Wiring is not my area !
i would like to keep it as 6 volts if possible but its looking like its not easy ! for me anyway :?

The bike has a new wiring harnes and is standard spec..
apart from the solid sate rectifier..
Alternator wires as follows...
Green and White wires from the alternator going to the diaganal aposed horizontal conectors of the rectifier.
Orange from the alternator going again to the ignition switch...

Brown wire from the 3rd horizontal connector on the rectifier going to the ignition switch.
Red from the vertical connection of the rectifier going to Pos earth...
Image

Not sure what to do lol... :headbang:
Renegade2018
Posts: 4
Joined: Mon Sep 30, 2019 4:17 pm
Location: Hampshire

Re: 250 Model 14 alternator Wipac to Lucas

Post by Renegade2018 »

Paul R
Posts: 43
Joined: Sat Sep 09, 2017 6:04 pm
Location: west yorks UK

Re: 250 Model 14 alternator Wipac to Lucas

Post by Paul R »

Sounds about right . Wired as Janet said rectifier earth ok etc. Should start it up and see what the ammeter reads with and without full lights on (though they do dance around a bit when revs get up ). That should give you a good idea if things are ok. Good luck .
Locked