Sorting the electrical system
Motorcycle electrics are generally blissfully reliable for which you, younger readers, should be suitably thankful.
Us doddery old greybeards can remember the last rites of the British motorcycle industry and the frankly farcical electrical systems foisted onto the customers of the 60s and 70s. Not for nothing was the supplying company’s founding father known as Joe Lucas the Prince of Darkness!
The earliest Japanese bikes came with electrical systems that were simply from another mind-set and were paragons of virtue yet not totally infallible. Just like anything which involves amps, voltages and the like Enemy Number One is resistance. Some resistances are good and without them bulbs wouldn’t illuminate, yet other resistances can and will hamper electrical circuitry which is why we’re looking at it here. Little is more irksome than pressing the starter button then seeing the wiring of your freshly sorted bike puff out clouds of bilious grey, PVC scented, smoke.
Almost without exception every single electrical item will need to be properly earthed. Think of the earth as being the return side of any circuit. If that side of the system isn’t fully functional then the current will take an alternate and least path of resistance – torching stuff on its merry way. Starting at the very basics, ensure that the battery earth lead that runs to the frame or chassis is both in good condition and secure at either end. On older bikes things such as indicators are earthed via their metal bodies and/or their mounting bolts.
The subassembly they are bolted to may be rubber mounted i.e. rear mudguards and the like. And if that mudguard isn’t properly earthed the indicators, tail-light etc. won’t work properly. Same up at the front end; headlights often rely on earthing out via the bearings in the headstock that are swamped by grease which is generally a good insulator! A separate earth wire here won’t ever go amiss.
So enough about earths, let’s look at resistances in a little more detail. Wiring connections are normally made via either bullet connectors or dedicated connector blocks and both will suffer from moisture driven corrosion. If a brass connector appears green and/or crusty that’s corrosion you’re looking at. It’s the product of moisture, metal and corrosive salts and happens naturally. The various sheaths and fittings used by the manufacturer will keep the worst of these guys out but over time the inevitable occurs. The good news is that you don’t automatically need a need new wiring loom as most can be saved without issue.
The discrete components of bullet connectors are known as male and female; the analogies are hopefully obvious. Male bullet connectors can be easily cleaned up with a piece of Scotchbrite abrasive pad and some electrical cleaning fluid; Servisol Super 10 is the one to go for. With female sockets, a Dremel and a small brass brush can be used to evict any corrosion. A complete loom can normally be sorted in half an hour.
Block connectors require a little more thought and dexterity and here a set of small needle files and some tiny metal brushes will be useful. With the corrosion removed another blast of Servisol Super 10 should be applied to each and every connector. Broken or damaged wires are best sorted via a proper repair. Look online for a company called Vehicle Wiring Products who offer metre lengths of the appropriate coloured cable along with connectors, crimping pliers and everything else needed to repair a loom. Just one wiring lash-up can torch your bike so a few quid invested here seems like money well spent.
Heat shrink tubing can be useful for repairing or strengthening existing wiring but never rely on insulating tape to do anything substantial. It tends to let go over time and leaves a vile sticky residue. Looms may look as though they are wrapped in insulating tape but they aren’t. Only the start and end of any coverings are secured with self-adhesive tape; everything else you see wrapped in tape is bound by non-adhesive loom wrapping which allows the cables beneath it to flex and shift as the bike moves. Don’t trap those cables with sticky tape.
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