CT70 Schematics

[69ST]

... didn't like the way it looked and it made it hard to follow. I didn't realize there were different switches.

I think most members here, who have done their own wiring work share that same experience and opinion of the schematics.

As for the switches, most would have no way of knowing that about the subtle differences (let alone so much as suspect they exist)...and how most can be made to work properly under nearly any circumstances. That kind of experiential knowledge can only be gained the hard way...unless someone shares those lessons.

 

[Adam-NLV]

I spent 25 years in the Air Force as an electronics tech and 20 years teaching electronics at two different community college

I worked for the US Army for several yrs and a degreed electronics technician.
After scheduling our base for closure, they sent me to this AutoCad 3d training course for 6 months

If I had this AutoCAdd software on my computer.. i could make schematics of the different year wiring harnesses. But doing this drafting /and drawings by hand would be for a younger dude than myself.
If anybody has this 'Autocadd Software' on disk... I would be up for a agreement? or deal.

 

[Oldgreenpaint]

I found this thread and am reviewing it, trying to figure out a problem I am having with my 1971 ct70. Owned it since 1982 so switch and harness are original. I changed the old harness with a new one. Now the bike will not start or run when switch is in ignition position, with battery connected. Disconnect the battery, and it starts and runs great. Found the original part had a Honda part number of 098-6711. The repo harness I bought is for a KO, or so I believe. The Repo harnesses don’t reference original Honda numbers, so struggling with this some. Seems to have something to do with the two black wires at battery connector. Old harness shows continuity at just one black battery wire to black pin of switch connector. (switch out of the circuit). Repo harness has continuity at both black wires of battery connector to the black pin of switch connector. It is like the jumper wire at the battery connector isn’t even needed.

 

[lukelaw1]

post a link to the harness you bought, the black wire (ignition loop) at the battery connector is to inhibit the bike from starting at all without a battery in place, as we know running without a battery will blow some expensive headlights and instrument bulbs. so when a battery is in place with the black wire (ignition loop) and the key in the on position you have spark, how the bike turns off is the black wire is grounds to the frame through the ignition switch, I am wondering if the new harness doesn't match colors to the ignition switch.

 

[kirrbby]

I am wondering if the new harness doesn't match colors to the ignition switch.

I think Luke is onto it with this ^

The original harness was wired so to use that black loop...to insure you had a battery installed for the bike to run. But the aftermarket wire harnesses' do NOT need the black loop. They build the aftermarket harness to LOOK the same as Honda's harness, so you don't question it...but those 2 blacks at the battery plug have continuity...without the battery harness' loop/jumper.
I don't think that is your problem.

 

[Oldgreenpaint]

post a link to the harness you bought, the black wire (ignition loop) at the battery connector is to inhibit the bike from starting at all without a battery in place, as we know running without a battery will blow some expensive headlights and instrument bulbs. so when a battery is in place with the black wire (ignition loop) and the key in the on position you have spark, how the bike turns off is the black wire is grounds to the frame through the ignition switch, I am wondering if the new harness doesn't match colors to the ignition switch.

Thanks for the help Luke. Here is the link.

https://hondanuts.com/products/04-wiring-harness-honda-ct70k0-k0h

i can say for sure that the wire colors bothe sides of the new battery and new harness do not match both sides of connector

 

[Oldgreenpaint]

I will double up on the other thread post, in case someone sometime runs into the same crazy issue that I experienced. It turns out that the battery connector was assembled incorrectly at the factory and I just didn’t recognize it. Not used to seeing blue wires associated with a battery and not paying attention. So what I did is de-pin the battery blue and one of the black wires and swap positions. So all colors of the battery connector matches the same colors at the harness connector. Now the bike operates as it should.