Author Topic: Neutral light.....  (Read 744 times)

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Offline BallAquatics

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Neutral light.....
« on: March 19, 2018, 05:59:43 PM »
I recently installed the dash lights for my '74 CB550.  They all work correctly except the neutral light comes on when I pull in on the clutch lever.  The wiring hasn't been altered from stock and I attached the wires matching the colors inside the headlight housing.

Thanks in advance- Dennis
Dennis...  74 CB550  79 CBX  82 Seca Turbo  2011 CBR  2012 NC700X

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Offline greenjeans

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Re: Neutral light.....
« Reply #1 on: March 20, 2018, 06:02:30 AM »
take another look at those wires.   The neutral switch is a simple circuit.   1 wire - typically light green/red.  It will go from the actual switch to the head light bucket where it plugs into the wire that goes straight to the bulb.   The bulb will have 12v black wire coming from it.  When in neutral, it grounds and completes the circuit, lighting the light.
Sound like you may have a starter motor safety unit ?   If that is the case, I think that wire is a darker green/red.   If you have those switched, it looks like you would light the lamp as well.
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Offline eatpez

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Re: Neutral light.....
« Reply #2 on: March 20, 2018, 07:25:53 AM »
I just finished wiring my 750F1 but it looks like the CB550 wiring is a little different. My guess is that something is up with the starting motor safety unit but I have no idea what's going on inside that little box. Lots of folks get rid of them when rebuilding.

Offline Alaxy Galaxy

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Re: Neutral light.....
« Reply #3 on: March 22, 2018, 05:29:23 PM »
There's probably something amiss with the "starting motor safety unit" (it's probably just a box with a diode). Pulling the clutch makes electric starting possible, but shouldn't light the neutral indicator. Having the bike in neutral does just about the same thing, but also turns on the neutral indicator.

Offline HondaMan

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Re: Neutral light.....
« Reply #4 on: March 22, 2018, 06:01:14 PM »
If the safety circuit's diode is shorted, this will also happen. The bike works OK, it just indicates silly things.
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