SIP speedo - on and of and on and off

[Knowledge]

I have done a bit of work on a mate’s scooter but now the SIP speedo is playing up. I have tidied a lot of power cables but not played with the SIP speedo cabling.

When the engine is running, the SIP speedo come on for a couple of seconds, and then off for a couple of seconds and then on again and then.....(repeat). The on and off seems very regular, not just a loose wire.

When the engine is off, the SIP speedo does not do this.

It is a six pole DC system that worked previously.

Any thoughts?

[Fast n Furious]

If the rectifier / shunt regualtor has failed, then this may be the cause. Too much incoming ripple voltage into the SIP's 5V regulator box will cause it to shut down, reset and reboot, which will repeat continuously until the incoming voltage is stabilised. A cheap n cheerful scope meter would show the DC voltage stability and AC ripple voltage of the scoots regulator when the engine is running.

just out of interest...... Does it still do this when the main headlights are switched on?

[Knowledge]

A plausible explanation FnF. I will investigate the headlight scenario that you highlight.

Thanks