1978 CB750 Right Controls Help

jeffthompson55

New Member
I've just got a new kill/start switch for my bike (right hand controls), but according to the wiring diagram, there's three wires that come from the start button.
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you can see in the top in this diagram, that there are three wires for the starter. The black (ground) and a red/black wire and a yellow/red wire. The y/r seems to be for the starter solenoid, while the red/black is connected to a fuse, which I assume turns the headlight on. The new controls I have no only has two wires, one for ground and one for the start. Is there a way I can set this up without having to use the red/black connection? Maybe use an independent switch or something? What's the easiest and simplest way to go about this?
 
First up, black isn't ground. It's power. Power goes into the switch and then (with the kill switch on) it goes out to the coils. The same black power wire also supplies power to the solenoid when you press the starter button. When not pressing the starter button, the power is routed to the headlight (though the fuse box).

Most aftermarket switches do not have this functionality, so you need to find another way to send power to the headlight. Any thick black wire in the harness will do. Connect the brown/red wire from the left hand controls to a thick black wire in the harness. You should be able to use the one that was connecting to your old right hand controls.

For the new switch, is there a kill switch or only a start button?
 
So just connect the brown/red from the headlight wires on the left side to the black wire on the right, ok. That will bypass and keep the headlight on even when I push the starter?

It comes with a kill switch as well.
 
jeffthompson55 said:
So just connect the brown/red from the headlight wires on the left side to the black wire on the right, ok. That will bypass and keep the headlight on even when I push the starter?

It comes with a kill switch as well.

Correct. Headlight will always be on unless you want to wire up a five pin relay. I can provide instructions for that if you need them.

For the kill switch, one wire to black in harness (same black as starter button is OK) and the other wire to black/white.
 
I'm all wired up now, with the black/red wire rerouted to a solid black wire, bypassing the starter. As soon as I plugged it in, I can't start the engine. I'm not sure that any power is getting to the right controls now with nothing happening from both kill switch or starter. Nothing is hot on the right side now. 911 please what do I do to get the right controls back on??
 
So my right hand controls (kill/start) still have no power being run through them. After playing with it a little, I found that the negative terminal on the battery becomes hot (exothermic) after the ignition is turned on. Is this indicative of a short somewhere in the wiring? The main fuse is still in tact, should I just start ripping apart the harness to see if some wires have fused together or something? I obviously won't be turning the key back on until i understand the problem.
 
Possible, but any draw big enough to heat up the battery cable is definitely going to be blowing a fuse. All the connections are tight?
 
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