I nearly have all the 12v stuff done. I’m really just waiting on a relay that I want to use to turn on the 72 volt contactor. It’s a special relay called a “latching relay” that uses permanent magnets to keep the switch connected after an intermittent pulse of power is applied. This way I can use the start button to turn the main contactor on. If I used a regular relay I’d need a switch. There is no kill switch on these aftermarket handlebar switches or I’dve just used that.
Relays and contactors are simply switches. Switches that utilize electromagnets to close a circuit. The purpose of the smaller, latching relay is to allow normal 12volt switches and wires to power its magnetic coil, closing the circuit that I have connected to the 72volt main contactor. So a little switch is turning on a big switch, which allows higher voltage and amperage to power the motor. The 72 volt switches and cables need to carry 72volt, and 200amps continuously, which would totally fry/melt most 12 volt components which usually carry less than 15 amps @12volts.
The 12 volt system is most of the normal motorcycle wiring…horn, headlight, brake light, turn signals, keyswitch, etc. It sounds simpler than it is though. For instance, the two left and two right turn signals are switched by a handlebar switch that gets its power delivered through a flasher relay (which basically just turns the power on and off to makes the lights blink). Simple right? Right. Then you have to also connect the four turn signals to the hazard switch. You can never feed one side off the other, or all blinkies will flash whether you switch left or right. Then the two rear blinkies need to also be connected to the brake light, which is connected to the front brake lever as well as the rear brake pedal. Then all the lights also have a running light feed, and maybe some led indicators that tell you if you forgot to turn your blinkies off or if you’re driving around with your high beam on. Then I’ve got all of this stuff running through a little fuse box, and a main light switch, plus a keyswitch on the bars. Needless to say it’s a lot of fucking wires, switches, connectors, and soldering.
That, and I’ve not used anything from the original bike. Well I did salvage the original rear brake switch, which I mounted in a different position. But all the wires, switches, and connectors are new.
Cut down the brake light, and welded a bracket to mount the license plate in a way that doesn’t mess up my pretty fender.
Headlight, running, and blinker all on at the same time:
Little key switch in a mount I made from a couple of pieces of bar stock welded together. I decided not to run the spedometer/odometer. I’ll be using a cycle analyst anyway which makes that blob redundant.:
Next I need to start getting serious about the battery packs…