Topic: 1972 CL 100 Ignition Switch Wiring

[campbmic]

Hey guys, I just picked up a '72 CL100 scrambler thats in pretty good condition but sitting in storage for about 10 years. It looks like someone disconnected the ignition switch and I'm having trouble hooking it back up. The switch has 3 terminals on it, one labeled "G", one labeled "B", and one without a label. The unlabeled terminal has a short green wire connected to it and the other two are bare.

Close by are a red wire and a black wire. I'm assuming the black is ground and goes to G while the red is hot and goes to B. I'm just not sure what the unlabeled terminal with the green wire is supposed to go to. If anyone has advice please let me know! I tried googling but everything I found was for CB100s and it just shows a red and black wire. I'm not sure what the green is for but it looks stock.

PICS: https://imgur.com/a/GqIaqCS

I cleaned out the tank, put a new fuel filter in, and connected the black wire to G and red wire to B. I gave it a couple kicks to get gas into the carbs and turned the key on and it started up briefly. The bike has around 6k miles on it and is pretty nice!

[bryanj]

All the Hondas i have worked on red is live, black is switched live and green is ground but no idea why a ground is on the switch.
You really need to find a wiring diagram for that bike.
On the uk forum a member has uploaded to his dropbox a lot of manuals and parts books you could look there

[grcamna2]

I have a book with an early(1973)Honda CB125S and electrically,they are the same as your 72' CL100.
Do you have the original ignition switch in the bike:was the wiring harness damaged ?

[campbmic]

I have a book with an early(1973)Honda CB125S and electrically,they are the same as your 72' CL100.
Do you have the original ignition switch in the bike:was the wiring harness damaged ?

Everything looks bone stock but who knows what the previous owner did. Even the keys look like they're from the 70s, so Im pretty sure its all stock. No damage to the wiring harness. I'm assuming the green wire has something to do with accessory power? The green wire also has the same eyelet (but on both ends of the short wire). I'm guessing it goes to either ground or hot but dunno which one.

[grcamna2]

I have a book with an early(1973)Honda CB125S and electrically,they are the same as your 72' CL100.
Do you have the original ignition switch in the bike:was the wiring harness damaged ?

Everything looks bone stock but who knows what the previous owner did. Even the keys look like they're from the 70s, so Im pretty sure its all stock. No damage to the wiring harness. I'm assuming the green wire has something to do with accessory power? The green wire also has the same eyelet (but on both ends of the short wire). I'm guessing it goes to either ground or hot but dunno which one.

? 

Take a couple pictures and upload them?
I want to see the end of the switch wires/colors,also carefully slide the rubber cover off the back of the key switch and take a picture of the back of the switch and how the wires connect;take a similar picture of the wires in the harness(and their colors)where the switch connects to the harness.

[newday777]

I have a book with an early(1973)Honda CB125S and electrically,they are the same as your 72' CL100.
Do you have the original ignition switch in the bike:was the wiring harness damaged ?

Everything looks bone stock but who knows what the previous owner did. Even the keys look like they're from the 70s, so Im pretty sure its all stock. No damage to the wiring harness. I'm assuming the green wire has something to do with accessory power? The green wire also has the same eyelet (but on both ends of the short wire). I'm guessing it goes to either ground or hot but dunno which one.

That picture doesn't have stock connectors on it. Is that the switch?

[newday777]

A new switch number shows available. Call to confirm tomorrow when they open in Washington state. Pacific time.

35100-324-761

(I included a picture of what your switch should look like)

https://www.southsoundhonda.com/--xpartsstream#/s/HOM//35100-324-761//1/y

[Sw1ssdude]

Your switch seems to be from a different model. CB/CL 125/100 switches have pigtails attached to the switch, with japan style bullet connectors.  here you can find a wiring diagram:
https://4-stroke.net/download/overview-of-all-categories/wiring-schematic/1458-honda-cl100-wiring-schematic.html

Does your key fit the steering lock or the helmet holder?

some small hondas with magneto ignitions have green wires to the switch, amongst 4 in total: Red (hot) Black (switched hot) Black/White (ignition) Green (ground). these bikes use the battery only for DC components like the horn or brake light. The ignition power comes from the magneto (part of the alternator).

in the OFF position, red and black are disconnected, to keep battery from draining, but black/white and green are connected, to prevent power from the alternator getting to the coil. no spark, bike doesnt run.

in the ON position, red and black are connected, all lights function as designed, but black/white and green are disconnected, now the power from the  alternator has to take the detour through the coil to reach ground again, instead of being grounded in the switch. sparkplug sparks, bike runs.

are you sure your switch says 'G'? could it be 'C', like 'Common'? in this case i would assume that your 'Common' port is connected to either of the other two, depending on the switch position (connected with one on OFF; and connected with the other on ON). this switch setup would be a more elaborate system for a magneto ignition (which the CL100 does not have).

[campbmic]

There are images in the first post. Its probably a little confusing but the picture with the red and black wires is a plastic cover that goes on the back of the ignition switch to keep the wires out of the elements. When you put that cover on the switch then you'd essentially have the switch newday posted with red and black wires coming out of it in a pigtail connection.

On the backside of the switch (what gets hidden by the cover) you have the three terminals. A short green wire with eyelets on each end was connected to the blank terminal and the other end was disconnected. I'm assuming it should go to the G (which I've connected the black ground wire to) and the B (which I've connected the red hot wire to).

[bryanj]

BLACK IS NOT GROUND

[Sw1ssdude]

Yes, i saw your attached picture. Your switch has three screw connectors, all the honda switches i have ever seen have pigtails (short cables) soldered to the backside, either with bullet connectors, or combined in a plug. I have never seen a switch like yours, but i am almost 100% positive that this switch doesnt belong to your bike.

Does your ignition key work with the helmet holder or the steering lock?

As brian said: black is NOT ground, its switched power. Red is battery plus.  Green is GROUND. If you twist red and black together you successfully hotwired your bike (dont forget to de-hotwire it after use). If you manage to hook up red and black to your odd ignition in a way that the OFF position interrupts connection and ON brings them together, your're all set. Never mind that green cable dangling on the back side of your ignition switch, GROUND is not running through the ignition switch in an original cl100 wiring harness. Did you manage to open the wiring diagram link i sent you?