I am adding spotlights to my '89 and would appreciate it if someone could draw me a wiring diagram. I prefer to have them on all the time with the headlamp but, if it is best to add a switch, that is fine with me. Each bulb has 2 terminals on the back as shown below. Thanks

 

The one terminal on the spotlight is for 12 volt power and the other is for ground. They may be labeled + for power and - for ground. If they are not labeled then sometimes it does not matter which terminal is used for what, but sometimes it does. If the ground is in the wrong spot the light may not work at all or it may be dimmer than it should.

I personally would wire a switch to the spotlights even if you plan to leave it on all the time. It's nice for you or a future owner to have the option to turn them off.

Below is a very basic drawing. You basically want to get power from the low beam wire on the headlight. You can get the ground from a lot of different places including a bare spot on the frame. The switch gets installed inline on the power wire headed to the spotlights. Just make sure it's before you split the power to the two spotlights.



On late model bikes the low beam wire is usually yellow, high beam is white, and the ground is black. Black is almost alway a ground, but your high and low beam wires may be different. You may have to use a circuit tester to find out which is which.


If you tap power from the headlamp then you also may want to install an inline fuse for the spotlights so that any malfunction doesn't knock out your headlight. When splicing into wires do not twist them together or use butt connectors. Always solder and use heat shrinks to protect the wires instead of electrical tape. You want to make sure the wires are weather proof and won't come apart since your lights are for safety.

I hope this helps. Good Luck

 

Thank you for the diagram!

 

You probably want to use a relay to power the spots rather than tap into the headlight low beam to power the spots. You could use the low beam to close the relay and battery power (fused) through the relay. You could also have a switch.

 

I would use a relay anyway, to provide power to all three. The wire that currently switches on your headlamp will go to the relay, to switch that, hence the stock light wire carries very little current. A new wire direct from the battery to the lights carries the power, hence by-passing the stock wiring. If you buy a normal auto lights relay it should come with a wiring diagram.

 

Well, after calculating the amp draw for all 3 lights, it was way less than the stock headlamp relay was rated for so, I felt comfortable using the one relay for all 3.