CB500 loses electrical power when key is in 'On' position

Icon · Borekit Bruiser Joined: 21 Dec 2013 Karma :

Hey,

Got a 2001 CB500 with 34,500 miles.

Sometimes the key won't turn on electrical power when the key is in the 'On' position in the ignition switch. I have to wiggle the key a bit to get the dash lights to come on and for the starter button to work. The electrical power can go randomly when idling, turning the engine off, and I then need to move the key around again. I'm afraid to ride the bike in its current state in case the power cuts mid corner or when overtaking.

I put some WD40 into the ignition barrel in case there was some moisture, but problem still persists.

Any ideas why this is happening?

Thanks in advance for any advice.

cb1rocket · World Chat Champion Joined: 30 Jan 2010 Karma :

take the lock off and take apart and clean up the contacts on the base or a buy a new one off ebay.
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Amber Phoenix · Traffic Copper Joined: 01 Feb 2013 Karma :

No idea if you have the same issue, but my wife's CBF500 had a dodgy electrical fault where we couldn't get it to start, nowt from ignition on pressing starter button. Traced it back to the wiring loom under front seat, where its route has a dip and had water collected in it. It's also at this dip where it forks off to the main fuse and battery. The water had caused a tonne of corrosion at this T-junction, upon unwrapping it was just a mush of green corroded copper. Had to splice in some replacement wire and rewrap.

Might be worth a check if you CB has a similar routing on the main loom and any water clogging.
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WD Forte · World Chat Champion Joined: 17 Jun 2010 Karma :

From what you write and given the year and mileage, I'd say its highly likely
the copper switch pads and/or wiper mounted below the lock barrel
have worn.
I'd disconnect the cables and check continuity on the terminals
with a meter while working the switch a few times before buying
just in case.
Squishing WD40 in the barrel may help the lock tumblers but not the contacts
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