Brake light wiring

:blink: I have a vetter trunk on my 1980 KZ1000 Cop bike that has four lights across the back that are regular tail lights. I want to convert these lights to be tail lights and brake lights. There are only two wires going to the trunk. I need to know exactly what I need to do to convert these lights over. I assume that I will need to change the light sockets and add at least one wire to the mix that goes to the brake lights. Will I have to add a relay or anything else like that, and can I tap the brake lights anywhere along the line.
Can anyone out there get me a drawing or exact instructions on what I need to do? I can do the work if I have clear instructions.

Are you saying you want them to be running lights and brake lights? In other words, regular bright running and maximum brightness on brake?

If so, you need dual filament bulbs and sockets so you can wire all the low wattage filaments in parallel and tie them to 12V switched. Wire all the higher wattag filaments in parallel for brake light use.

I'd go with LEDs for this because an additional four lamps is a lot of extra power to run all the time.

I have a Vetter trunk on my KZ 550 LTD. I have rewired the trunk lights so the outer ones are turn signals and the inner two act as brake lights.

You will need to replace the 3 wire connector and it's mounting plate on the trunk with a 4 wire one. I got a set of microphone connectors from Radio Shack. tinyurl.com/66kdvf

I like this style connector as it allows me to remove the trunk easily if I want. It's an easy wire job, one ground wire which jumps to all four lights, one wire to both brake lights, one wire for each turn signal.

I've tried LED bulbs in these lights but have not been happy with their performance. They have a very narrow field of view so unless you are standing (riding/driving) directly behind the bike they seem very dim. Oh, and I didn't need to use any relays.

If you need it, the standard Kawasaki turn,stop, and tail light wiring colors:
1. Right turn signal = GRAY
2. Left turn signal = GREEN
3. Brake light = BLACK WITH RED STRIPE
4. Tail light = RED
5. Ground = BLACK WITH YELLOW STRIPE

I am not sure where folks are getting color codes but I will try and help. Remove your seat and the tail piece on your bike... the Kaw wiring harness will also have a sub-harness that connects the rear turn signals and tail/brake lamp. Find the connector that connects the sub-harness to the main harness.

Since you currently have four bulb holders in the fairing tail lamp and taking into consideration that your bike makes finite amount of voltage and such, I personally would consider converting two of the bulbs to become a brake light and two remain as running lights.

To do this, find the junction connector between your main wiring harness and the tail-light sub-harness.

The brake light wire will be dark BLUE. The running light wire will be RED and the turn signal wires will most likely both be gray. Sometimes one is gray and one light green. There will also be a ground wire black/yellow.

Anyway, splice into the BLUE wire which runs down to your tail lamp and run a piece of wire into the trunk. Just cut the hot wire connected to a couple of the bulb holders and splice in the blue wire. That will give you both brake and running lights on the trunk. Of course, the running lights won't be as visible.

If you don't like this idea, just say so as the bulb holders can be replaced and more modern bulbs used for more visibility but it is more work as well.

Vter Bob wrote:

I've tried LED bulbs in these lights but have not been happy with their performance. They have a very narrow field of view so unless you are standing (riding/driving) directly behind the bike they seem very dim.

The only ones brighter than incandescent bulbs are the 3W Luxeons or 5W Luxeons. They are blinding bright.

Thanks for all the good information. I think,(but don't know for sure) that my Cop bike has a higher output electrical system and will be able to run two element lights in all four sockets. I really want them to work like they do now but add the brake light feature. It appears that at one time there were three wires in my trunk, but somewhere along the way one was removed and only the two wires required to let them work as regular tail lights remain.

I don't know what dimension your current bulb holders are or how much room you can go with new ones so you need to do some measuring. Once you have a handle on this, the autoparts store has two-filment bulb holders. They will surely have them for SAE type 1157 bulbs. Get four of those bulbs as well. I think they are 23/7 watts. Splice the blue wire connection under you seat and pull a blue wire to the trunk and split it four ways and connect to the brake light filament. You can tell which is which by applying 12VDC to each filament (use wires off the battery) while grounding with another wire off the negative battery terminal. Anyway, wire the red to the other lead off the bulb holder for the running light and you MAY have to fabricate a ground by attaching a wire to the metal part of the bulb holder which you would attach to the black/yellow or run to a bolt on your frame nearby.

Last, I doubt the cop bike has any different generator/stator or higher output charging system but I could be wrong. You need to double check and do some calculation as the four lights will have quite a bit more draw when the brake is pressed. Keep in mind that you will be on a 10A circuit I think so the 10A is limiter and not just the bikes total voltage. You may need to put the lights on a separate circuit turned hot by a triggered relay. If this is the case, you can refer to my coil repowering article on our website under wg's Tech Stuff... the relay would work the same if powering the brake/running lights OR ignition coils.