clutch safety bypass

vandito.cb

vandito.cb

Been Around the Block
after years of avoiding anything involving wiring, i've finally gotten comfortable enough to do some of my own and it's been great so far, but...

i've decided to clean up my whole front end and doing away with the clutch safety switch leaves me with the need to bypass it. i removed the entire main harness out to clean up and remove unnecessary wiring so i have the diode exposed right now. my question is...without just grounding out the safety switch wire up by the headlight harness, is there a way to do away with it (and the diode) without disrupting the neutral light as well?

i still want to retain a functioning neutral light although i don't want to have to meet the criteria of clutch in, in neutral to be able to start.

the bike in question is a 1981 cb750f

TIA
 
Let's take a look at the diagram.

Clutch switch has two wires.

We can follow those wires to see that one wire is grounded and the other leads back to the solenoid (labeled starter relay).

What you can't see from the diagram is that the wire that leads back to the solenoid is the ground wire for the energizing coils. Without a connection to ground, the solenoid won't work.

So how does the solenoid get grounded? Clutch switch is one option (since we can see the switch's other wire is a ground wire). The second option is the neutral switch (which we can infer by tracing the other branch back to the diode).

So why the diode? Well... a diode is a device that only permits current to flow in one direction. What happens if we remove the diode from the circuit? We end up with two grounding points for the solenoid (which we already have with the diode in place), but we also end up with two grounding points for the neutral light, which we did not have before. With the diode in place, the neutral light can only be grounded by the neutral switch. Without the diode, your neutral light would light up every time you pulled in the clutch.

Going back to what the solenoid needs. The energizing coil needs power (coming from the start button, so no change here) and it needs to be grounded. For "safety" purposes you can just remove the clutch switch and ensure the green/red wire remains ungrounded. If you're really wanting to dig into things and simplify it, you can ground the green/red wiring coming from the solenoid, directly. This will bypass the neutral switch as well as the clutch switch and let you remove a bit of wiring (if that's your thing). Of course the starter motor will kick in anytime you press the button, so be careful.
 

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Sonreir said:
If you're really wanting to dig into things and simplify it, you can ground the green/red wiring coming from the solenoid, directly. This will bypass the neutral switch as well as the clutch switch and let you remove a bit of wiring (if that's your thing).
Click to expand...

i'm really just looking to leave the in-neutral criteria intact while removing all wiring previously associated with the clutch switch...essentially as it never existed.

i'm removing as much wiring i'm not using as possible which is why i didnt want to just jump the switch at the bars.

the info is appreciated.
 
and also, Sonreir, my ignition switch harness has two brown wires running from it; one that i understand runs out to the tail/brake lights and the other one, from a separate terminal loops right back into the other one.

i'm assuming this is for lighting up the rear while the key is in P, now can i do away with that looped wire if i dont want to run anything in P?

my new light switch has a function to kill all lighting on the bike and i figure having the key on ON to light all accessories i want on would essentially be enough to control when i want the tail light on or off.

summed up, it's my understanding i can run one brown wire to my light switch as opposed to my ignition switch and do away with any need to have a P function.
 
Yes, you can.

Make sure to reroute the brown wires to splice into the black, though. The tail light often only gets power through the brown wire, so you can't just disconnect it and leave it hanging.
 
Sonreir said:
Yes, you can.

Make sure to reroute the brown wires to splice into the black, though. The tail light often only gets power through the brown wire, so you can't just disconnect it and leave it hanging.
Click to expand...

oops...

i've since snipped it, assuming it's nothing more than something that lights up when i don't need it to. with my current light switch, i can opt to cut power to the tail and headlight (as well as a separate engine kill switch all on the same switch...pretty neat) so i figured in the midst of replacing and relocating my fuse box, I can run the head and tail light on the same fuse, technically still giving them power from the keyed power black wire anyway.

pls correct if wrong.
 
I meant "snipped it" as in i snipped the looped brown one. i still have the main brown from the tail tied up front waiting to get paid to splurge at vintage connections.
 
Why dont my lights are clutch lights are the starter button dont work I have to jump it from relay the kill switch works
JPEG_20260620_125932_276207415973501329.jpg


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