Electrical what is that for

Information relating to the Matchless G5 or AJS Model 8 350cc Lightweight
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Electrical what is that for

Postby Rupert123 » Sun Sep 10, 2017 5:19 pm

I decided today to have a look at the electrics on my 350 G5 they could do with some TLC to put it mildly i took the headlamp off and pulled the wiring out and hanging off a terminal block connected by 3 brown with blue striped wires was a piece of pvc 1/2" water pipe about 4" long inside the pipe was some sort of ceramic resistor
the same length it looked like a fuse wire wrapped around it was connected to the terminal block.
Anyone have any ideas i have uploaded two photos of this creation.

Martin.
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Re: Electrical what is that for

Postby ajscomboman » Sun Sep 10, 2017 5:29 pm

As you quite rightly guessed it's a resistor which takes the place of the original clear coated resistor wire in the original wiring harness. It was an upgrade of it's time and has now been replaced by the 6v solid state regulator rectifiers sold by the likes of Paul Goff, etc etc.

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Re: Electrical what is that for

Postby Mick D » Sun Sep 10, 2017 5:34 pm

Hi

Google is your friend:

http://www.google.co.uk/url?sa=t&rct=j& ... SRR1zzPVtw

No idea what it's there for though - why not replicate the original wiring - though from the photo that looks like it could be a challenge :

Regards Mick

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Re: Electrical what is that for

Postby Rupert123 » Sun Sep 10, 2017 6:45 pm

Thanks for your replies ,from my limited knowledge i gather from what you say this was a modification ,the solid state rectifier does not need the resistor.

Martin.

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Re: Electrical what is that for

Postby ajscomboman » Sun Sep 10, 2017 7:10 pm

No a resistor will not convert ac to dc you still need a rectifier for that and I'm sure you'll find it under the seat bolted to the mudguard where the original selenium type would have been. I suspect it'll be a little square solid state one. The resistor merely helps control excess charging current ie' acting as a form of regulator to protect the battery from boiling. The new solid state regulator rectifier would mount under the seat in place of the original and you could do away with the resistor in the headlight.

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Re: Electrical what is that for

Postby Rupert123 » Sun Sep 10, 2017 8:22 pm

I was slightly confused about the resistor ,under the seat i have that square plate solenium device nothing else so i fit the solid state rectifier remove the old rectifier and that resistor and i guess find a home for the three wires that connected to resistor.Just another quick one regarding the electrics does the ammeter have a light like the speedo.
Cheers Rob,

Martin.

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Re: Electrical what is that for

Postby Expat » Sun Sep 10, 2017 9:16 pm

Hi Rupert,
Not sure how similar your G5 wiring is to my G3. Mine never had a resistor to my knowledge but had the plate type rectifier mounted under the seat. Problem of over charging occurred when I fitted LED lamps...there was nowhere for the excess alternator output to go.

Solved this by obtaining one of the aforementioned solid state 6 volt rectifier/regulators, which means even when main beam is on during daytime riding, the battery is still getting a charge, but no overcharging. :D

Needless to say, advice given here enabled me to find the answer to the problem. :)

Top forum for help and advice.

Btw, no lamp in the G3 ammeter, may be different for your G5 though. Good luck with your wiring, looks a bit dodgy in the pics.

Best regards, Steve
Keep shiny side up.

These are my principles, if you don’t like them, I have others. (Groucho Marx)

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Re: Electrical what is that for

Postby Ozmadman » Sun Sep 10, 2017 11:17 pm

If you fit a modern solid state reg/rect from Paul Goff http://www.norbsa02.freeuk.com/goffyelectrex.htm you get rid of the resistor in the headlamp and the rectifier under the seat.. I bolted my unit onto the rear mudguard.. Its simple to do and here are the wiring instructions in advance. You can get a 6 or 12volt option... I left mine at 6 volts and it is a brilliant conversion

Remove battery
Remove old rectifier note the colours of wires
Bolt new unit to mudguard, does not have to be earthed.
You have Wipac alternator so the coloured wires will be light green, orange and white coming from alternator, remove plate covering gearbox and you will find a four way bullet conector, remove conector, using single conector join the two maroon wires this wire goes to the points.
Using another single conector join the two white wires, the white should go to the old rectifier
Using a double conector fit the light green and orange (from the alternator) so they become one wire and fit the light green (from the old rectifier0 to the other side. You will have a spare orange wire down by the four way connector, just insulate it and leave it hang
The two green or yellow wires (sometimes they are yellow sometimes green) from AREG are conected to the light green and white wires from the the old rectifier, it doesn't matter which way round, the red from the AREG goes to earth/frame and the black goes to the brown which was the DC output from old rectifier and is the live supply to the ammeter as on your drawing.
Thats it,
The AREG comes with instructions, if you buy from Paul Goff you can ring him for advice, he is very helpful

Also, there should be a bulb holder which clips onto the outside casing of the speedo the bulb from that lights up the speedo and ammeter I HAVE ATTACHED A PDF FILE SHOWING IT IN THE HEADLAMP
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Paul
1960 Model 8
1974 Yamaha RD250B US Model 6 speed

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Re: Electrical what is that for

Postby Expat » Mon Sep 11, 2017 2:08 am

Paul,
Great instructions you posted, very helpful, was able to fit my Areg6 on the inside of the battery/toolbox where the original rectifier was. Neat pic in the PDF also, did you fit and rewire new switches? They look very tidy.
Steve
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Re: Electrical what is that for

Postby Rupert123 » Mon Sep 11, 2017 3:22 pm

Notes and pdf,s on the regulator and installation are outstanding Paul really helpful you have done a really neat job on the wiring something to aspire to ,Steve was correct in saying there is top advice and information to be had from people on this forum.
I will fit one of these regulators and i think i will keep to 6 volts.

Martin.

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