Tail/Brake light wiring for aftermarket light

I just picked up this tail/brake light for a KZ750 cafe project. My harness has three wires - one tail, one brake and one ground - but the light only has two wires - a brake and a tail - so where should I connect the ground wire from the harness?

Thanks,
Chris

Here's a link to the light...

cgi.ebay.com/ebaymotors/Model-A-Tail-Lig...%26otn%3D5%26ps%3D63

It has two wires, power and ground. There is no brake light function on that light.

the ebay ad says its for a Ford Model A. the old Model A's did not have the dual function taillight/brake light so as stated above, its just power and ground. if you use a dual filament bulb, and wire the light yourself you could still get it to work.

I asked the seller about it and here's what he said:

"It is a brake light and a tail light. the top light is your brake, the bottom light is your tail. each wire goes to a diffent bulb. I believe there is a green wire and a black wire. The black wire is not ground, it needs to be hooked up. the green wire should be on top, so it should be wired into your brake, and the black wire should be on bottom, so it would be wired into your tail light. It grounds through the housing. You may have to run a seperate ground wire from one of the mounting bolts of the light up to the main portion of your frame depending on what you have it on and how its mounted."

For general info, the colored wiring for the brake light/running lights on most Kawasaki's is:

RED,running or tail light circuit.
BLUE,(sometimes with a red stripe)the brake light circuit.
BLACK with a YELLOW stripe,the ground circuit.

chrispysaki wrote:

I asked the seller about it and here's what he said:

"It is a brake light and a tail light. the top light is your brake, the bottom light is your tail. each wire goes to a diffent bulb. I believe there is a green wire and a black wire. The black wire is not ground, it needs to be hooked up. the green wire should be on top, so it should be wired into your brake, and the black wire should be on bottom, so it would be wired into your tail light. It grounds through the housing. You may have to run a seperate ground wire from one of the mounting bolts of the light up to the main portion of your frame depending on what you have it on and how its mounted."

Then you clean a spot on the metal frame and connect a ground wire.

Take the bulb out and make sure it is a dual filament bulb/socket. If not, one of the two wires is a ground.

chrispysaki wrote:

I asked the seller about it and here's what he said:

"It is a brake light and a tail light. the top light is your brake, the bottom light is your tail. each wire goes to a diffent bulb. I believe there is a green wire and a black wire. The black wire is not ground, it needs to be hooked up. the green wire should be on top, so it should be wired into your brake, and the black wire should be on bottom, so it would be wired into your tail light. It grounds through the housing. You may have to run a seperate ground wire from one of the mounting bolts of the light up to the main portion of your frame depending on what you have it on and how its mounted."

If there actually are two separate bulbs in the rear light fixture, the upper bulb could be a single filament brake light bulb, and the lower bulb could be a single filament tail light bulb.

Each bulb would receive battery positive voltage from its own separate wire to a single metal center-spot on the end of the bulb base.

The brass part of the bulb surrounding the glass would ground to the bike frame via the bulb socket.

Dual filament bulb has two spots on the end of the bulb base, being one for the brighter brake light filament, and another for the tail light filament.

Good Luck!

Sorry if these questions seem stupid, but does that mean that I shouldn't ground the mounting bolt to the ground wire in the harness?

chrispysaki wrote:

Sorry if these questions seem stupid, but does that mean that I shouldn't ground the mounting bolt to the ground wire in the harness?

If the design of the rear light fixture, when attached to the bike, provides a ground connection between the bike frame and the bulb sockets, such ground connection will equate to battery negative, in which event the harness ground wire won't be needed.

Then all that's otherwise needed is a battery positive feed to the single metal center-spot on the end of each bulb base (being the brake light wire feed to the upper bulb, and the tail light wire feed to the lower bulb).

If the design of the rear light fixture, when attached to the bike, does NOT provide a ground connection between the bike frame and the bulb sockets, a ground connection may be fabricated by running a third wire from the fixture to the bike frame or to the harness ground wire. The idea is to provide a ground connection from the bulb sockets to the bike frame or harness ground wire.

Good Luck!