Mark’s Guzzi T3

Mark is production editor on Classic Bike magazine, which makes him an old friend. He bought this lovely old Guzzi ten years ago for £2200 and since then it’s done 20,000 miles – many of them on trips to the Piston Rally in Spain.

These trips often coincided with minor electrical breakdowns, which was the cue for his Rally mates to descend on the bike and perform emergency roadside surgery. But ahead of this year’s event Mark decided the bike needed a little TLC. His main observation was the starter button: it didn’t always work. But then I noticed the lights were iffy as well. The on/off switch had no effect, mainly because the lights had been wired to come on all the time (?!?). And one of the tail lights was dead.

It seemed sensible to sort all three. The starter button issue was obvious: when you press the starter or horn button on these little switches they earth to the handlebars. And the handlebars are held in painted clamps, so they aren’t earthed to anything else. The cure is to clean up one of the switch clamps, solder an earth wire to that, and run it to a decent earth in the loom.

As for the lights, I took time to crawl over the loom and figure out what each wire was doing, but really it was a question of snipping off all the horror and replacing it with fresh cable and new connectors. And bringing the on/off switch back into use. And making sure the earths were reasonably good.

Mark rode the bike to Spain this year as usual, and it didn’t miss a beat. “I finally finished the 5000 Curvas at the third attempt – 500km in a 12-hour day in the Picos. Finished in Santander in the dark and rain. Thanks for fixing my lights!”

You can read more about how to repair an ancient wiring loom in the November issue of Classic Bike, out October 23. And in the same issue, you’ll find Mark’s exploits on the Guzzi in Northern Spain.

If you own an old bike and you don’t know Classic Bike, give it a go. It’s a really good magazine.