Finished With No Sense of Discomfort by Diversion from the Same Manufacturer. Convenient Functions are Added by Modifying the Handle Switch

The handlebar switches on out-of-print vehicles have a variety of personalities, depending on the make and model.
While it is true that the newer the bike, the better the functionality, the retro look that evokes a nostalgic atmosphere is also hard to discard. Let's explore the possibility of upgrading a beloved bike with a low-priced handlebar switch by porting parts from a higher-end model.

Push-cancel, passing, and hazard functions are still useful.

A steering wheel switch that was seen on many Kawasaki vehicles in the early 1980s, before the blinkers were push-canceled. On the left switch, the horn and passing button are integrated, and on the → switch, the starter switch and engine stop switch (kill switch) share the same button. A cap is installed to the right of the dimmer switch, which looks as if it was blocked later.

This is the left switch with the hazard switch that was purchased for parts. Since there is a dedicated circuit for hazard and the shape of the coupler is reversed (the OEM coupler is female while this switch is male), and the clutch lever switch is also different, only the hazard switch part was transplanted to the stock switch.

The internal shape of the housing is nearly identical with or without the hazard switch, so porting the switch appears to be relatively easy. Those with the factory hazard switch also have more wires that attach to the dimmer switch board.

The hazard switch to be implanted as a component is a simple rocker switch, with orange/green going to the relay and green and gray going to the left and right turn signals. When switched on, they function as hazard lamps by simultaneously sending a flashing current to both sides.

A handlebar switch is not just a control device; it is one of the most important parts that enhance the individuality of a motorcycle. Good operability is important, of course, but it is also often a feature of each model.

For example, the most popular indicator switch on current models is the push-cancel type, but before the 1980s, there were sliding switches, switches integrated with the dimmer switch that switched the headlights up and down, and some models with the horn button on top and the indicator switch on the bottom. There were also models with the horn button on top and the indicator switch on the bottom. The 1980s Kawasaki model shown here has both the horn and the passing switch in one unit, and the functions are used differently depending on the way the button is pressed.

Whether or not they were easy to understand and use has been proven by subsequent history, but it is certain that they were at least parts that symbolized individuality. In the current world of discontinued and old motorcycles, it is widely recognized that not only functionality and performance improvements, but also nostalgia for the parts that were used back then, even if they were not as easy to use, is another way to enjoy discontinued, and the original specifications of the time tend to be respected.

Nevertheless, just as it is impossible to switch a cell phone from a smartphone back to a racket, it is also true that once you get used to a useful feature, you find it inconvenient not to have it. We should not use them blindly, but passing and hazard lights are certainly useful features if they are available. Modifications that divert genuine parts from older models to add them are also common and can be purchased as general-purpose parts.

On the other hand, if you want more functionality but still want to keep the retro look, you can upgrade the handlebar switch by diverting parts for a higher-grade model. There is a limited condition that the switch of your car is a low-cost model and there is an advanced grade in the same family, but if a part of the steering wheel switch is covered with a cap, there is a possibility of adding functionality.

While some models of left-hand handle switches on Kawasaki vehicles, which were common in the Z-GP and GPZ-F era, have the hazard lamp switch integrated into the right side of the dimmer switch, some models have a lid over that area.
In this case, the hazard function can be added without compromising the design of the factory handlebar switch.

Hazard function ported from the handlebar switch of the same series model

Check the wiring color and function of the OEM switch and the diverted switch with a tester. The OEM hazard has a special relay separate from the indicator relay, and there is wiring for it on the body side. The factory harness without hazard has no such wiring.

Although a general-purpose switch could be installed around the steering wheel and gauges, this switch allows the hazard lamps to function with a factory-style finish. The wiring was cut long in order to bring out the OEM color.

By replacing the indicator relay with a wide type compatible with 1-100W, the hazard switch can be interrupted in the circuit of the factory indicator. If you have wire strippers that can strip the coating not only at the ends of the wiring but also in the middle, it is convenient to connect the wires without cutting the existing wiring.

The wiring color is also identical because it was diverted from a model of the same manufacturer and the same age. After soldering the hazard switch wiring, the indicator wiring should be disconnected from the indicator switch in order to insulate it with a heat shrink tube.

Once insulated with heat shrink tubing, solder to the original indicator switch terminals. Before securing them to the switch housing, make sure that each indicator and hazard functions properly.

The hazard function was added without modifying the factory wiring outside of the switch. The area that was blocked by the cap was originally where the hazard switch should have been installed, so there was no discomfort at all.

When upgrading a steering wheel switch, it is easiest if the entire switch can be diverted.
However, even if the switch looks similar, the wiring specifications may be different for different models installed.

Even for the models introduced here, the coupler at the end of the harness without the hazard switch originally installed in the vehicle has a female terminal, whereas the coupler with the hazard switch has a male terminal and cannot be connected to the harness on the vehicle body without modification. In addition to the different shapes of the male and female couplers, the terminal arrangement of the switch harnesses may also be different for different models.

It is possible to replace the entire switch by lining up the two switches and checking the wiring color and changing the coupler of the diverted switch to the same female terminal as the factory one, but since the switch housing shape is the same and only the hazard switch is needed, only this part is removed and transplanted to the factory switch.

Since the switch housing is only in the same family, we were able to port the hazard switch with minor modifications, but some ingenuity is required to add the switch wiring. Most models with OEM-installed hazard switches have a dedicated hazard relay. The model from which the switch was diverted also has a blinker relay and a hazard relay, and there are wires leading to each relay.

This means that the coupler at the end of the switch wiring has a male terminal that connects to the two relays on the body side. On the other hand, the model to which we are going to add the hazard switch does not have a hazard relay, to begin with, so there is no wiring for the hazard on the steering wheel switch either.

Although it is possible to install a new relay and run dedicated wiring, it may be possible to change the existing indicator relay to a wide LED-compatible type, which can be accommodated by simply changing the wiring in the steering wheel switch. Since the specifications of the OEM indicator relay are determined according to the power consumed by the two front and rear lamps plus indicators, it is not compatible with hazard lamps that have four flashing lights (front, rear, left, and right).

However, recent high-performance indicator relays have a super wide range of 1 to 100 W that can be used from LEDs with extremely low power consumption to the 80 W class that uses 4 x 21 W (or 23 W) indicator bulbs at the same time, which is common in indicator bulbs.

When using a wide-type relay, the hazard switch is newly interrupted in the wiring leading from the relay to the indicator switch. When the indicator switch is operated, the flashing current flows only to either the left or right indicator, but when the hazard switch is operated, the current from the relay flows to both the left and right indicators, thus functioning as hazard lamps.

The same relay activates both blinkers and hazards, so hazards have priority, but even if two relays are installed, the result is the same, since hazards will start blinking if the hazard switch is turned on while blinkers are in use.

This modification can be applied to other models that have had hazard switches added in the middle due to minor changes. It is worth keeping in mind as a technique to add a new function without changing the atmosphere of the OEM switch.