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Bike runs but no other electrical systems. All fuses are ok. Any ideas?

Check the fuse that is 'loose' running from the battery. My 500 had this 'fail' - no electrics except ignition.

It was the fuse holder, not the fuse itself, the spring had lost tension.

Hi, I don't appear to have such a fuse, where is it located? The other issue is the battery is not holding a charge, although the charging circuit appears to be working. It sparks across the terminals when the bike is running but still won't run the lights or anything else?

If your bike is wired normally, the red wire from the battery +ve terminal should go straight to a tubular fuse holder located under the r/h side panel. As MickeyMoto says, these are prone to failure, especially 40 years down the line! For your exact symptoms, that is a likely source of trouble. Other possibilities include the ignition switch or of course any number of possible disconnected wires.

It's not a great idea to short-circuit the battery, especially with the engine running, that is very likely to blow the fuse or damage the voltage regulator. Use a known accurate voltmeter to check the battery. It should read greater than 12v under all conditions and with the engine running at medium revs, you should see around 14v if it's charging correctly.

Good luck with it, electrical faults can lead you on a merry dance all right!

Joe.

Thanks, I will have a look for the fuse holder in question.

No sign of an in line fuse in that box. All the other fuses are in there on the fuse block, and there is the box below: the 'adjuster' I believe. This is a 77 Strada, so am assuming the always have an in-line fuse somewhere? And could a failed battery explain this? It was new 6 months ago but the bike gets spasmodic use.

Hi,

As already mentioned...

1. Measure battery voltage with engine off. ~12v
2. Measure voltage with engine running. As you rev it it should increase to ~14v.
3. Check your earths. Take them off, emery cloth them until there is bare, clean metal then reassemble. Do you have an earth lead from the engine to the battery?
4. Check the fuses. You should have ~12v on one side of them all and the same on the other with the ignition on. I believe the rectifier / regulator needs a battery connection. The blue book has all the details.

Good luck,

Mike

Thanks - a job for the weekend

Turns out to have been a failed battery. It was new in November but sporadic use meant it never really got charged properly. A new one, and a good old clean of all the earths and other connections, seems to have sorted things. We shall see how long it lasts.

Good news. Now buy an Optimate charger... - or not... some people like them some do not. I have always rated them to keep batteries charged and they do other 'maintenance things', too to keep the battery 'optimised'.

Other brands are available. I believe Lidl or Aldi used to do one for bikes.

Or fit a PC680,run the bike for 10 years,not much in winter,never charge it remotely and it works as good as new,cranking my starter motor with impunity.