Neutral light circuit

Paul Marx

Hero member
Location
France
Just to make sure I'm getting it right. The neutral light on my wife's 500 is constantly on. The bike has been partially rebuilt and no doubt, I've got a couple of wires mixed up, it worked normally before.

There's a + feed to the neutral light. The neutral switch closes the circuit by earthing when neutral is selected, and the green light comes on. Normally.
In the present case, there must be another earth somewhere causing the light to stay on, is that correct? The charge light in the same instrument goes out when the engine is running.
I've tested the wire going from the neutral light to the neutral switch, no volts so the light is earthing somewhere?

Paul
 
check what Sock suggested, disconnect wire from the switch, if light stays on then yes there must be another earth somewhere

very much doubt that is the case, you need to shim the Neutral switch to make correct contact, to me you do not have the correct shims in place so not only does the switch make contact with the wire upset on the shift drum in neutral it is also making contact with the shift drum itself when not in Neutral, but that generally makes Neutral and 1st/2nd gear hard to change into as the protrusion of the Neutral switch plunger is too far

another possibility is the wire itself is earthing out somewhere
 
Thanks to both. I've done that already and the light stays on so I'm going earth chasing, or I'll run a separate feed to the light if I can't find anything.

The neutral switch originally on the machine wasn't shimmed at all making neutral selection nigh impossible. It was leaking oil, so has been changed and shimmed to 1.5mm. but until the electrics are sorted, I can't shim it properly.

Paul
 
You don't need working electrics to check the switch function, a simple multimeter is fine. Put gearbox in neutral, you must have continuity to ground from the switch terminal, select a gear, continuity goes away... doesn't get much simpler. Also helpful for checking shimming vs. shift action.

piet
 
Many thanks to all. problem solved.
The rubber bung holding the bulb holder was perished, and the bulb holder was earthing against the instrument chassis.

Now to chase other problems, but on my bikes. 🤪

Paul
 
All the globe rubber sockets were stuffed on my bike. Bought new sets from these dudes. Very good quality.

 
All the globe rubber sockets were stuffed on my bike. Bought new sets from these dudes. Very good quality.

A good address. Put aside for my next delve into an ND instrument.

Paul
 
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