Topic: removing clutch safety switch--CB400f

[jessezm]

Hey folks!    I'm completely re-doing the wiring on my CB400f cafe project.  My new clutch does not have a safety switch, and I wanted to know how best to remove the switch wiring from the harness.   It seems to be linked up to the neutral switch as well, but the wiring passes through some sort of diode.  Can I remove that altogether?  Thanks

[Bodi]

The system is fairly simple. The ground on the slolnoid switch (starter motor relay) does not go to ground. The +12V power wire on the solenoid is powered directly through the starter switch. The clutch switch is connected from ground to the solenoid "-" or ground wire on the solenoid: this enables the starter motor whenever the clutch is pulled in. There's also a diode ffrom the solenoid "-" wire to the neutral switch which connects to ground when in neutral. This allows electric start when in neutral, the diode isolates the circuits so the neutral indicator light doesn't come on whenever the clutch is pulled in.
To remove the clutch switch you just have to ground the "-" wire from the solenoid directly. One solenoid wire gets start power from the start switch (this should be "ignition" power from the keyswitch so you can't spin the starter motor with the key OFF) and the other goes to ground. You can ditch the diode and all that wiring and connect the neutral switch directly to an indicator lamp that also gets "ignition" power from the keyswitch.

[jessezm]

Perfect, thanks, Bodi!

[Joel]

Isn't there only one diode?

Won't rewiring as specified allow starts with the bike in gear and the clutch out?

[Bodi]

yes, only one diode. Remove it and the bike will not start in neutral with the clutch engaged.
The clutch lever switch is directly connected to the colenoid, no diode. This is the "master" starter interlock, the clutch muct be pulled in to start. The neutral switch is a bonus extra through the diode.
With the clutch switch removed and the wiring altered (sounds like he wants to make a whole new harness) the starter motor will work regardless of gear or clutch position.

[Joel]

I haven't carefully inspected the wiring on mine, but the clutch switch has been missing since I purchased it.  I believe it will only electric start with the bike in neutral.  I should check to see what's been done with the two connectors from the clutch switch.

[jessezm]

True.  Hopefully I've been riding long enough for it to be ingrained in me never to hit the starter without pulling the clutch and looking for neutral...

Not doing a whole new harness, but I am altering a lot of what's there.  I'm relocating the electrics and battery a bit, moving the ignition switch (I think), using solid state rectifier/regulator, aftermarket signals, gauges, hand controls, etc, and an electronic ignition with dyna coils.  I was going to do away with the idiot lights altogether, but my mini speedo has them incorporated, so what the hell...  I'll be tackling all this over the next few weeks while I wait for my tank and seat to (finally) arrive.  I'll document it all for the still-nonexistent build thread ;-)

[jessezm]

Oops, didn't see your post--yes, please report back.

I haven't carefully inspected the wiring on mine, but the clutch switch has been missing since I purchased it.  I believe it will only electric start with the bike in neutral.  I should check to see what's been done with the two connectors from the clutch switch.

[Joel]

I'd imagine they could simply be left unconnected and the neutral switch interlock would still function as it did originally.  If left unconnected, they'd need to be insulated with something to keep them from grounding to any metal surfaces nearby.

[Bodi]

It won't do any harm if these wires touch ground. One wire is ground anyway, the other would just allow starting in gear should it connect to ground.

[Joel]

It won't do any harm if these wires touch ground. One wire is ground anyway, the other would just allow starting in gear should it connect to ground.

True.