Spare switch wire?

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maylar

maylar

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I want to use the "spare" push button on my MKII right side switch cluster for the start button on my new e-start. The wiring diagram shows it as white/red , and I found it in the connector cluster under the tank. However it has another white red plugged into it that goes into the wiring harness, while the diagram shows it as being unconnected. I have verified that battery power is on the wire when the button is pushed.

Where might the other end of that wire go? If it's in the battery compartment somewhere I won't have to run a wire down the backbone.
 
maylar said:
Where might the other end of that wire go? If it's in the battery compartment somewhere I won't have to run a wire down the backbone.
Click to expand...

Yes, it should emerge in the battery compartment along with a white/purple (ballast bypass) that would have also connected to the starter solenoid if one had been fitted.
 
L.A.B. said:
Yes, it should emerge in the battery compartment along with a white/purple (ballast bypass) that would have also connected to the starter solenoid if one had been fitted.
Click to expand...

So, the good news is that I found a white/red and white/purple wire in the battery compartment. The bad news is that the white/red has no continuity to the one in the bullet cluster under the tank. I dunno where that wire goes, but I had to run my own.
 
Coming out of the wiring harness just above the carburetors you should be able to see two white/red striped wires that have spade type connectors on them. You need to splice those two wires together to complete the starter circuit.

The only reason that I can imagine for Norton to do that to the starter wires is that they possibly wanted to use a switch built in to the clutch cable. The clutch would then need to be pulled so that the starter can be engaged. Of course this is only my speculation.


Peter Joe
 
PeterJoe said:
The only reason that I can imagine for Norton to do that to the starter wires is that they possibly wanted to use a switch built in to the clutch cable.
Click to expand...

Not back then. That sort of stuff didn't show up until long after Norton was out of business.
 
maylar said:
on my MKII right side switch cluster
Click to expand...

1. The PREMKIII harness white/red wire up front has the bullet end(1).
2. mid back bone, along with the engine red ground are 2 white/red 1/4 fast-ons. one(2A) goes forward to the (1) bullet. The other white/red(2B) goes to the rear and comes out
3. 1/4 faston white/red (3B) with the white/black 1/4 faston
this whole set of wires are not documented on the 72-73 wiring diagram.
I suspect it was part of the failed 20M3S/200000 starter and is why it was left out of the drawn schematic..
 
PeterJoe said:
The only reason that I can imagine for Norton to do that to the starter wires is that they possibly wanted to use a switch built in to the clutch cable. The clutch would then need to be pulled so that the starter can be engaged. Of course this is only my speculation.
Click to expand...

Or, an electrical cut-out possibly (sensing alternator output as in the 3AW) that prevented the starter motor from operating after the engine had been started.

MexicoMike said:
Not back then. That sort of stuff didn't show up until long after Norton was out of business. I think it was at least the middle '90s, maybe later, when that was implemented. In fact, None of my 90's bike's had it. Don't recall when it was mandated but I'm thinking it wasn't until the '00s.
Click to expand...

Well, BMW airheads from 1969 had a cut-out system to prevent the electric starter from being operated with the bike in gear.
There was also an electronic device in the starter relay to prevent the starter operating once the engine was running although not used on later models presumably because it was considered unnecessary as the starter motor has an overspeed clutch but the 'in-gear' cut-out with a clutch override switch remained.
Edit:
Japanese bikes from the early-mid '70s certainly had a cut-out to prevent the starter operating when in gear unless the clutch lever was pulled in.

Edit:
CB750 starter safety system from the early '70s (pdf download):
http://manuals.sohc4.net/cb750k/service_manual/SM750K_7.pdf
pdf p.26-28
 
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Interesting data, you guys are a treasure trove of information. I have a 72 that I’d love to ad an e start and use that spare button. I believe I have those same wires by the battery. Just want to confirm that those wires go to the spare and are a possibility for the e starter. Thanks
C
 
To surgeon said:
Just want to confirm that those wires go to the spare and are a possibility for the e starter.
Click to expand...

Yes, white/red would have been the electric start button wire if they had actually got around to fitting a starter motor before 1975 and white/purple would have been the solenoid to coils ballast resistor bypass wire.
 
W/R wire 1
handle bar switch to bullet

W/R wire 2
bullet at font of main harness to mid backbone 1/4 faston

W/R wire 3
1/4 faston mid backbone TO battery area 1/4 faston
(paired with wire 4, W/B 1/4 faston)
 
To surgeon said:
I seem to have those wires in both the battery compartment and under the tank, is that possible?
Click to expand...

And.....the WP (ballast bypass) would have connected the starter relay/solenoid to the existing ballast to coils(-) WP wiring but that section isn't on the wiring diagram presumably because the wire was never used (prior to the 850 Mk3).

To surgeon said:
I assume the one under the tank is best for tapping an e start?
Click to expand...

Depends what you mean? It could be used for the relay or solenoid connection but power to the starter motor would come from the battery.

Edit: I think the electric starter kits generally come supplied with the necessary wiring in which case, connect according to the instructions.
 
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To surgeon said:
Thanks
I assume the one under the tank is best for tapping an e start?
Click to expand...

I wasn't aware of the 'mid backbone' pair, so I unplugged the bullet at the main harness and ran my own white/red back to the battery compartment to operate my starter relay.
 
"Japanese bikes from the early-mid '70s certainly had a cut-out to prevent the starter operating when in gear unless the clutch lever was pulled in.

Edit:
CB750 starter safety system from the early '70s (pdf download):
http://manuals.sohc4.net/cb750k/service_manual/SM750K_7.pdf
pdf p.26-28"

Interesting...During the '70's I bought brand new:a Honda 350 scrambler, a Honda 550 4, a Honda CB750, and a Honda CB750F. Don't recall any sort of cut-out re the starter on any of them. The only reference to "neutral" or the starter in the owners manual as far as starting that I remember on any of them was a statement to ensure that the neutral light was 'on' before engaging the starter. But there was no reference that I remember saying that the bikes would not start in gear. But maybe it wouldn't and I just never happened to try to start it while in gear without pulling the clutch in. Seems hard to believed that with all four of them I never tried it/experienced that they wouldn't start if they weren't in neutral. ;)
 
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MexicoMike said:
Interesting...During the '70's I bought brand new:a Honda 350 scrambler, a Honda 550 4, a Honda CB750, and a Honda CB750F. Don't recall any sort of cut-out re the starter on any of them.
Click to expand...


As I said, Hondas such as the early CB750 had to be in neutral for the starter to operate........

Spare switch wire?


...however, by the mid-'70s clutch switches had been introduced that allowed the bike to be started in gear if the clutch lever was pulled, and my '75 CB400F and '76 CB550F1 both had a clutch switch.

https://www.cmsnl.com/honda-cb400f-european-direct-sales_model14640/switch-clutch_35360341000/

https://www.ebay.co.uk/itm/153565762251

http://forums.sohc4.net/index.php?topic=71266.0

http://forums.sohc4.net/index.php?topic=76893.0

Spare switch wire?
 
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