Charge lamp - blue wire no voltage?

[black pearl]

Hi Guys

I've been slowly working on installing a Motogadget M-unit Blue on my R65. I've also installed the ChronoClassic too.

I've managed to get most of it working except for the charging lamp? Am I right to expect to get a voltage on the blue wire coming from the starter when ignition is on.

I've had a 12v incandescent, and now one of the original globes.

Any ideas?

[georgesgiralt]

No voltage on the blue wire at the bulb when engine not running.
It is a ground. This make the bulb glow brightly.
When the engine runs, the alternator output some voltage so this wire goes from 0V up to battery voltage at which point the bulb has two positives on it's terminal and, thus, stop glowing.

[black pearl]

hi George

Of course....I get it now. Will go try that and I'll report back.

[black pearl]

Thanks for the tip.

Worked a treat. I mistakenly thought the blue was hot and the return from the globe when to earth.

All good now.