wiring 1953 g80s with club loom
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Dave Corey
- Member
- Posts: 1
- Joined: Fri Mar 04, 2022 12:00 am
- Location: Quebec CANADA
wiring 1953 g80s with club loom
looking for advice for using wiring loom from club. I feel I should have made my own.
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Groily
- Member
- Posts: 2159
- Joined: Thu Jul 04, 2002 1:00 am
- Location: NORMANDIE FRANCE
Re: wiring 1953 g80s with club loom
Not quite sure what sort of advice can be offered really, but here are a few thoughts in case they might help. Not sure when you say 'you feel you should have made your own' whether that's because the one you've got doesn't look as if it'll fit, or because you don't like the aesthetics, or what? But no matter . . . I imagine the harness is supplied with the appropriate diagrams, and colour-coded etc, so it should be fairly self-evident where things go, subject to the qualification that no generic loom can ever cater for every mutation done to a machine over 70 years, nor for different types of battery terminals, voltage regulator connections, variations from original in where bits are mounted, upgrades to such as headlight reflectors (eg H4 bulb fittings), and so on. and so on.
But anyway . . . luckily, there aren't many wires, so we're not talking serious electro-spaghetti here.
I think it's a good idea to spreadeagle the harness on a table or something for starters.
There are the charging circuit (dynamo, voltage regulator, ammeter and battery), the lighting switch and wires off it to the various bulbs, and there are the 'extras', ie brake light and horn. (With a magneto, no worries about ignition switches or any of that.)
If you look at the charging side first, you'll see two wires that go from the dynamo to the voltage regulator. And then two other wires that come off the regulator, one of which is a simple earth, the other of which ('A') goes to the Ammeter (or to the main switch terminal 3 with a short link to/from the ammeter), and then a separate wire runs back to the battery live side from the other side of the ammeter.
The dynamo wires (D and F) are probably in a common sheath for much of their length, and the regulator main output wire 'A' will be neatly bundled along with the other wires that need to go under the tank etc up to the headlamp area. That's the charging department.
If you then focus on the main lighting SWitch, you'll see that the main input terminal is number 3 as mentioned above, and that terminal 2 supplies the headlight via the dipswitch, with 4 and 5 doing side and tail + speedometer respectively. That's it for the lights, apart from the brake light. That will either be taken off the battery live side, or off the main ammeter-battery line somewhere upstream from the battery. The tail light wire will be included with the main bundle that passes under the tank, the speedo and front light feeds will have been taken out of the bundle at appropriate places leaving the necessary lengths to hook them up to the dipswitch (headlight) and to the sidelight and speedo bulb holders directly.
There will be a main earth lead, heavy gauge, to connect to the battery, and another earth or two, to attach to the bullet holder(s) adjacent the headlight reflector.The brake light wires will also probably be sheathed with the rear part of the tail light feed to make a neat cluster headed towards the rear licence plate under the rear mudguard.
The only other thing is the horn, which is 2 wires, with it being earthed through the push button on the combined horn/dipswitch, or maybe by a separate horn-only button. Those wires will dangle from the harness at a suitable spot - there are variations there depending on where the horn actually is on one machine compared with another.
With the harness spread out it should be quite easy to figure. There may be some redundancy built-in, there may be the odd extra thing to add in, but what you have should be a good basis.
It is generally regarded as good practice to run a separate earth wire from the headlamp shell to the frame somewhere, to avoid things having to earth through the greasy steering head, and it is also important to think 'Fuse' if the harness doesn't make provision for these things. The fuse needs to cover everything if there is just the one being used (say 20 Amp for 6 volt systems, 10A or a bit more on 12v). The brake light and horn need to be covered, if they are taken directly from the battery. If using an electronic voltage regulator, several manufacturers counsel a fuse in the 'A' lead from the box of tricks, which the harness might not cater for.
There shouldn't be the need for much lateral thinking or head-scratching on one of these, as that will have been done by the bloke that made the harness.
But anyway . . . luckily, there aren't many wires, so we're not talking serious electro-spaghetti here.
I think it's a good idea to spreadeagle the harness on a table or something for starters.
There are the charging circuit (dynamo, voltage regulator, ammeter and battery), the lighting switch and wires off it to the various bulbs, and there are the 'extras', ie brake light and horn. (With a magneto, no worries about ignition switches or any of that.)
If you look at the charging side first, you'll see two wires that go from the dynamo to the voltage regulator. And then two other wires that come off the regulator, one of which is a simple earth, the other of which ('A') goes to the Ammeter (or to the main switch terminal 3 with a short link to/from the ammeter), and then a separate wire runs back to the battery live side from the other side of the ammeter.
The dynamo wires (D and F) are probably in a common sheath for much of their length, and the regulator main output wire 'A' will be neatly bundled along with the other wires that need to go under the tank etc up to the headlamp area. That's the charging department.
If you then focus on the main lighting SWitch, you'll see that the main input terminal is number 3 as mentioned above, and that terminal 2 supplies the headlight via the dipswitch, with 4 and 5 doing side and tail + speedometer respectively. That's it for the lights, apart from the brake light. That will either be taken off the battery live side, or off the main ammeter-battery line somewhere upstream from the battery. The tail light wire will be included with the main bundle that passes under the tank, the speedo and front light feeds will have been taken out of the bundle at appropriate places leaving the necessary lengths to hook them up to the dipswitch (headlight) and to the sidelight and speedo bulb holders directly.
There will be a main earth lead, heavy gauge, to connect to the battery, and another earth or two, to attach to the bullet holder(s) adjacent the headlight reflector.The brake light wires will also probably be sheathed with the rear part of the tail light feed to make a neat cluster headed towards the rear licence plate under the rear mudguard.
The only other thing is the horn, which is 2 wires, with it being earthed through the push button on the combined horn/dipswitch, or maybe by a separate horn-only button. Those wires will dangle from the harness at a suitable spot - there are variations there depending on where the horn actually is on one machine compared with another.
With the harness spread out it should be quite easy to figure. There may be some redundancy built-in, there may be the odd extra thing to add in, but what you have should be a good basis.
It is generally regarded as good practice to run a separate earth wire from the headlamp shell to the frame somewhere, to avoid things having to earth through the greasy steering head, and it is also important to think 'Fuse' if the harness doesn't make provision for these things. The fuse needs to cover everything if there is just the one being used (say 20 Amp for 6 volt systems, 10A or a bit more on 12v). The brake light and horn need to be covered, if they are taken directly from the battery. If using an electronic voltage regulator, several manufacturers counsel a fuse in the 'A' lead from the box of tricks, which the harness might not cater for.
There shouldn't be the need for much lateral thinking or head-scratching on one of these, as that will have been done by the bloke that made the harness.