1958 Headlamp - Which switch?

Information relating to the Matchless G80 or AJS Model 18 500cc Heavyweight.
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schrottschlecker
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1958 Headlamp - Which switch?

Post by schrottschlecker »

Hello,

I would like to restore my AJS Model 18S as close to the 1958 specs as far as it can get. The headlamp shell has a hole in the top, where an ignition switch was mounted. I would like to close this hole. What was the correct switch for the 58 model? The 1958/59 wire harness diagram shows the combined ignition/ lighting switch. Was there also a version with light switch only (no ignition)? I cannot find a wiring diagram with alternator/ coil and simple light switch.

Many thanks for any feedback.

Christian
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Rob Harknett
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Re: 1958 Headlamp - Which switch?

Post by Rob Harknett »

http://archives.jampot.dk/technical/Ele ... C_1958.pdf
http://archives.jampot.dk/technical/Ele ... 8-1959.pdf
Things get complicated if you do not have all the correct parts. In the above links you will see correct Lucas parts and wiring.
schrottschlecker
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Re: 1958 Headlamp - Which switch?

Post by schrottschlecker »

Hello Rob,

thanks for the reply and the links.
There is some contradictory or missing information though: the image of the headlamp MCH57 shows the simple lighting switch (31340A) instead of the lighting/ ignition switch (31443E) that is listed as the correct one. Also the wiring diagram shows the ignition-/ lighting switch.

I am looking for the wiring diagram for the 18CS version without ignition switch. Does anybody know which cables to connect when you have a lighting-only switch (Lucas 31340A)?

Thanks,

Christian
SPRIDDLER
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Re: 1958 Headlamp - Which switch?

Post by SPRIDDLER »

schrottschlecker wrote:I cannot find a wiring diagram with alternator/ coil and simple light switch.
I think I'm right in that an alternator/coil ignition system MUST have an ignition switch to isolate the battery and prevent the coil overheating (when the points are closed)?
If the bike's ignition is by magneto an ignition switch isn't necessary and wasn't fitted.
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Rob Harknett
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Re: 1958 Headlamp - Which switch?

Post by Rob Harknett »

The bike appears to be coil ignition so surely will need combined switch. I believe the diagram given was OK for the wiring of that. If you only want a lighting switch, the fit a simple on off ignition switch elsewhere, that would need additional wiring. For a diagram of lighting switch only wiring, check say 1955 mag ignition 18S diagram.
schrottschlecker
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Re: 1958 Headlamp - Which switch?

Post by schrottschlecker »

SPRIDDLER wrote:
schrottschlecker wrote:I cannot find a wiring diagram with alternator/ coil and simple light switch.
I think I'm right in that an alternator/coil ignition system MUST have an ignition switch to isolate the battery and prevent the coil overheating (when the points are closed)?
If the bike's ignition is by magneto an ignition switch isn't necessary and wasn't fitted.
OK, that makes sence.
Is it also correct, that there is no regulator nor Zener diode in the alternator/coil models?
Mick D
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Re: 1958 Headlamp - Which switch?

Post by Mick D »

Hi

There is a rectifier but no regulator or zener diode.

Regards Mick
schrottschlecker
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Re: 1958 Headlamp - Which switch?

Post by schrottschlecker »

All right, the rectifier I found in the parts box. Now I need the ignition-/ lighting switch.

Thanks for your help.

Christian
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