® The Seven Deadly Sins of Custom Bike Building, Sin #3: Electrical Bad Practice

In the electrical realm, sadly, there is very fertile ground for bad practice. The worst offender here, visible on too many custom bikes, is the over-use of grounds. A "ground" in powersports vehicle terms simply means an electrical circuit path that consists partly of metal structures in addition to wire. There are different kinds of grounds. The best grounds are universal, the worst individual. A universal ground is one to which all the components on the motorcycle tie back through wire to a point close to or actually at the battery. An individual ground on the other hand is where the component grounds through itself, thus adding its mounting to the ground path. It should be intuitive that relying on a component's bolts and brackets to complete the circuit is frought with potential problems, and the more severe either the vibration or its operational environment, the more serious the risk is that the component circuitry will be subject to deterioration. Individual grounds are very poor practice but are frequently found on custom motorcycles and virtually never on stock production bikes.

Here's another one: Taiwanese keyswitches. A well-known aftermarket parts supplier and I got into quite a disagreement about this more than 20 years ago. He insisted that the commonly available Taiwanese keyswitches were vouched for by his supplier as "equal to OEM.". Not so, never have been, based simply on my experience. And now I see finally someone has done the research and discovered that all of these switches sold for large bikes are not only Taiwanese and some even Chinese, but they are all copies of a single factory Honda switch designed for a model one-third the size (and with commensurately far less electrical load). See my comments on what these keyswitches are made of also.

There are so many problems of an electrical nature on custom bikes it is impossible to list them all, but we can't leave this topic without addressing another very controversial item: electrical crimping. In my mind, crimping connectors onto wiring does a grave disservice to your motorcycle. I am well aware this is a minority opinion, but it can't be helped. Over ninety percent of electrical problems on vintage powersports vehicles are traceable to the presence of loose and corroded connectors. We don't see the same kinds of problems on vehicles made after the early 1990s because their connectors are sealed with rubber, and thus no moisture and dirt can get into the connector. But vintage stuff is not like this. The factory crimped-on terminals, continously exposed to the elements, gradually build up resistance until such a connector takes on the characteristic of a headlight bulb. That is, the connector, instead of being merely a conductor, begins to produce heat like a headlight. This is the reason regulator connectors and alternator connectors and starter solenoid connectors and even fuse boxes melt on 70s through 80s Japanese powersports electrical systems. Not, as so many in magazines and on the Internet suppose, overheated alternators and other components. The fact is, vintage Japanese electrical systems need their connectors disassembled and rebuilt, preferably before they melt down. This is easy to do, and it needs to be done only once.

If such is the case with the stock stuff, and it is, what in the world are folks thinking when they use crimp type connectors in their modifications to their machines. Do it right. And though it shouldn't need to be said, the ubiquitous Scotchloks are the worst-case scenario relative to this subject. Avoid them.

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