Neutral switch burnt out?

Merry Christmas all.
I’ve been happily rigging up a relay powered off a keyed positive, earthing through the neutral switch to bypass the sidestand cutout switch when V50PA (police issue) in neutral. I was reusing a glass cartridge fuse housing with too feeble a fuse, so once fuse failed, covered it in foil & carried on. Have clearly buggered the neutral switch, which now works once in a blue moon. Idiot- but I wasn’t really expecting power post relay coil to bugger switch.

  1. since switch works now & again, are they adjustable? I know I have to get battery tray out to access it.
  2. basic tenet seems sound, so I can have bike running while I lock garage, but should I put a ballast resister in series from relay to neutral switch to reduce current draw/heating. If so,what sort of ohm rating?
  3. come back Maplins, I miss you.
    All thoughts gratefully received.
    PS activating sidestand depresses switch which is then live (push to break) & relay buried under tank clicks, presumably cutting LT feed to coils.
    Ho ho ho. Matt

The neutral switch is a crude metal contact that earths out in the gearbox when neutral has been selected. It is behind the starter solenoid and will need the starter motor removing. The single wire to the switch is purple and runs straight to the neutral switch. As this is an earth wire adding resistance to it will not make it work any better but may make the bulb shine less bright when it works. The other side of the neutral bulb is a red wire that is common +ve feed to all of the warning lights except the main beam and lights warning lights.

If you remove the neutral switch it is easy to bend and you can experiment until it is bent in the correct way, or you could buy a new switch.

Good luck

Hi Chris.
There appears to be a very small mercy (in terms of dismantling) in that V50 neutral switch (GU19207220) is a plunger type on an 8mm thread & looks like a modified spark plug. Downside is it’s a sealed unit with a porcelain/white plastic tubular insulator out of which emerges a top hat shaped connector which connects to purple earth wire from neutral light (I’ve piggybacked onto purple wire to create to circuits in parallel, using switch as common earth).I haven’t pulled it out, but the photos seem to show it’s crimped/rolled construction à la spark plug & the only way to get at the electrodes (which I guess I’ve burnt/distorted) is with a dremel. New switch £50ish. Guess I can ponce about for a couple of evenings trying to replace contacts inside switch body, or stump up the cash, knowing it “should” drop straight in and work out of the box. What I can’t get my head around is how the bloody thing got burnt in 1st place.
Normal function is to earth a 1.2W bulb. If W=VxA, bulb uses 0.1A. By Mr Ohm, R=V/I or R=12/0.1, ie neutral bulb’s resistance is 120 ohms (I think- physics was never my strongpoint). Assuming internal resistance of relay coil negligible, if I shove a 120ohm (which sounds q little to prevent fuses blowing & melting contacts) resistor in series with relay will that stop me wrecking 2nd switch, as total load on circuit should now mimic that of neutral light circuit. Right. I need a lie down.
All opinions gratefully received.
Cheers all.

Worth checking to see if a car one, say from a Fiat will fit and be a lot cheaper.

How old is the switch? Could simply have packed up from old age.

Bike’s only got some 5000 miles on the clock only. It was the ampage shoved through it that’s done the buggering I suspect, not the number of gearchanges. Time for a new switch I guess.

Still don’t see how a relay coil would pass that much current. Also, to blow a fuse. What rating was the fuse?

Also, the only 5,000 miles doesn’t alter the switch being ‘X’ years old (I’m guessing 30+ if original) :smiley:

Contacts may be just furred up.

True. Thrift be buggered. New switch here so hope to to have it in this WE & then I’m off to local auto electrician. Will see if I can dremel resin off old one & disassemble to work out what happened.

I would be interested. :smiley: