Everyone seems to ask for wiring diagrams and not one bike is made the same, some have flashers, some don't, some keep the points and coils and some use an electronic ignition of some kind so I had the idea to put together these diagrams. Each diagram is part of the total and could run by itself. I have used a negative ground system and most diagrams can be used with either positive or negative ground as long as there are no polarity sensitive devices such as LEDs and electronic ignition modules The colors used are not what is fitted to any bike that came from the factory, they are different just to make the diagram easier to follow. A blue wire will carry current just as well as a yellow one

First lets get the motor running:

Here is the simplest ignition possible and this was fitted to the early Commando



Later on they added a ballast resistor and used 6 volt coils



Now here is how any electronic ignition is connected, for the specific one, refer to the manufacturer's instructions. All of them have a connection to the positive and negative of the electrical system, all of them (well, OK, most) have the coils wired in series if two coils are used. A dual output coil can be susstituted for the two coils. In some cases, the pickup may have more than two wires (Sachse) and in others the whole module fits in the poinst housing (Tri-Spark). On the Tri-Spark, the pickup is part of the puck, one of the old points wires is converted to bring voltage (+ or -) the other point wire is then connected to the coils while the last connection is made through the motorcycle's frame (again + or -), this is explained in the instructions that came with the unit, as you can see even the Tri-Spark classic has the same number of wires, some are just not visible.

Simple headlight diagram



Same but using an LED for the high beam indicator

Tail and brake light circuit diagram:

Basic flasher diagram:



Same but with an LED indicator



Using all LED "bulbs"

Here are the basic power generating diagrams. The first one is like the old stock POSITIVE ground and the other two are what would be wired with an integrated rectifier regulator like the Podtronic but with a NEGATIVE ground I have used conventional colors for these, not the ones Norton uses, usually on any electronic device, the black wire is negative and the red wire is positive.



The next two are for NEGATIVE ground using either a two or three phase alternator. Rectifier / regulators like the Podtronic are the same for either two or three phase, when used on two phases, they simply cut off the unused (yellow) wire.

Wow, that's great.

Taking requests? There was a bunch of talk about using relays, especially in the headlight circuit. What would that look like?

Thank You!

swooshdave wrote:Wow, that's great.

Taking requests? There was a bunch of talk about using relays, especially in the headlight circuit. What would that look like?

Here goes. Heavy wire, #14 is good for 17 amps, #16 for 13 amps, #18 10 amps or 204 watts, 156 watts and 120 watts respectively at 12 volts, will need to be run from the main fuse to the relays placed as close to the headlight as possible (in the headlight shell). The rest of the wires can be smaller gauge however, going to smaller gauge wires can lead to the wires breaking due to vibrations or movement not to mention the difficulty in attaching the connectors. I personnaly think this is overkill especially if the wiring is redone on a bike and good switches are used, the maximum legally allowed high beam (here) is 65 watts so even using #18 wires, the headlight should not see a major voltage drop, but everyone is free to do as they please.

Jean



The numbers refer to this type of relay, I found these for less than $4 at my local surplus electronics store.

HI I have a standard layered wiring diagram in color that I can add and remove items from.If anyone is struggling I will happily put together a custom diagram (Systems wirh relays excluded.. )

I personnaly think this is overkill especially if the wiring is redone on a bike and good switches are used

I agree, but in many cases we want to keep a stock appearance, so use the stock Lucas handlebar switches and key switches which show an alarming amount of voltage loss after 30+ years. Relays compensate for this and are fairly easily hidden under the tank or in the headlight shell.

As far as headlights go, I will do anything I can to get more light, even on my (relatively) modern bikes.

Ron L wrote:

I personnaly think this is overkill especially if the wiring is redone on a bike and good switches are used

I agree, but in many cases we want to keep a stock appearance, so use the stock Lucas handlebar switches and key switches which show an alarming amount of voltage loss after 30+ years. Relays compensate for this and are fairly easily hidden under the tank or in the headlight shell.

As far as headlights go, I will do anything I can to get more light, even on my (relatively) modern bikes.

Have to agree with this there can be a significant voltage loss across 30 year old lucas switch clusters in my case I have fitted a relay for the headlight and rear light, I like them to be as bright as poss pretty important safety wise...