Roadster Rear Tail Lights Wiring

[Quarterwarrior]

I am trying to wire the rear tail lights and I am having a hard time finding which wire goes to what light, top or bottom. I believe that I have to join a couple of wires from the harness to the connector, ie ground wire. I guess I am not sure what light does what? I am assuming that when you hit the brakes both top and bottom light up? What about the directional and parking light? What does the top light do, what does the bottom light do? I know it might seem like a dumb question, I just cannot find it anywhere.

Thanks for the help.

[edwardb]

Looks like this is your first post... Welcome! You will get better advice if you provide more information, like what version Roadster you're building, what wiring harness, etc.

The general answer is: Both fixtures have a dual filament bulb. One normal, the other one bright. Normally you wire both top and bottom normal brightness as the running lights (not parking) and all four are lit when the headlight switch is in the first (parking light) or second (headlight) position. Then the bright elements are used (typically) for the brake lights on the top fixtures, and turn signals on the bottom fixtures.

Each rear light fixture has three wires: Black is ground, green is the bright element (brakes or turn signal), red/yellow tracer is the running light.

Your harness to each side should have four wires: One for ground, one for running lights, one for brake and one for turn signal. You can share the ground between the two fixtures.

Normally recommended to use high quality weather proof connectors for all the light connections front and back. Like Weather Pack.

Does this help? Harder to explain than it really is.

[Quarterwarrior]

edwardb,

Thanks for the help, I think you covered exactly what I was looking for. I will give more info in future threads. It is a MK IV complete kit,Thanks again.

[Jeff Kleiner]

The complete kit uses a Ron Francis harness which is set up so that all 4 lamps are illuminated for tail lights with one on each side used for brake lights and the other on each side used for turn signals. Like edwardb I prefer to orient them so that the uppers are brake lights for better visibility.

Tan harness wire at each corner is for tail lights and will go to the low element on all four via the red/yellow lamp wire.

Purple harness wire at each corner is for brakes and will go to the bright element on one per side via the green lamp wire.

Yellow harness wire on the driver's side goes to the bright element on the second light assembly via the green lamp wire.

White harness wire on the passenger side goes to the bright element on the second light assembly via the green lamp wire.

Black wire on all joins with the black harness ground.

Cheers,
Jeff

[Pastenseverb]

I installed the lights as both Edward and Jeff have stated but I put a weather-pack plug on one of the lights so that I could remove them for paint or to replace without having to cut the wires. I did the front this way as well. Just an idea.

[lahrs37]

Looks like this is your first post... Welcome! You will get better advice if you provide more information, like what version Roadster you're building, what wiring harness, etc.

The general answer is: Both fixtures have a dual filament bulb. One normal, the other one bright. Normally you wire both top and bottom normal brightness as the running lights (not parking) and all four are lit when the headlight switch is in the first (parking light) or second (headlight) position. Then the bright elements are used (typically) for the brake lights on the top fixtures, and turn signals on the bottom fixtures.

Each rear light fixture has three wires: Black is ground, green is the bright element (brakes or turn signal), red/yellow tracer is the running light.

Your harness to each side should have four wires: One for ground, one for running lights, one for brake and one for turn signal. You can share the ground between the two fixtures.

Normally recommended to use high quality weather proof connectors for all the light connections front and back. Like Weather Pack.

Does this help? Harder to explain than it really is.

I know this is old but it was the exact info I needed. Thanks Paul!

[Al_C]

I know this is old but it was the exact info I needed. Thanks Paul!

That makes two of us! Thanks Paul and Jeff!

[RJD]

An oldie but it keeps giving. Very useful for me today. Thanks Paul and Jeff.

[Redlinejoev]

Wow this thread is very helpful and surprised to see it started 7 years ago. Thanks Jeff and Paul! I do hate to upset the status quo with my question but is there a way to wire this so that BOTH lights come on for the brakes? Seem to me if two brake lights are good why not four. Hope everyone is safe!

[65 Cobra Dude]

Joe,

You need a trailer wire adapter to make all 4 brights light up for brakes, blinkers and flashers. I just put one on my car and it works great.

Henry

[Redlinejoev]

Joe,

You need a trailer wire adapter to make all 4 brights light up for brakes, blinkers and flashers. I just put one on my car and it works great.

Henry

Henry,
I think I saw something like that on one of the websites, in fact it was a wiring diagram for the adapter. I thought it would simply be a matter of twisting some of those wires together. Shows how much I know about electrical wiring.

Thanks!

[davekp]

Joe,

You need a trailer wire adapter to make all 4 brights light up for brakes, blinkers and flashers. I just put one on my car and it works great.

Henry

Looking for the "adapter" hookup to operate all 4 brights for brakes but when I search for "trailer wire adapter" all I find is the plugs to hook up a trailer.
Can you give me some guidance?
Thanks!

[edwardb]

Looking for the "adapter" hookup to operate all 4 brights for brakes but when I search for "trailer wire adapter" all I find is the plugs to hook up a trailer.
Can you give me some guidance?
Thanks!

Probably "converter" is a better word to search on. https://thefactoryfiveforum.com/showthread.php?30470-Tail-light-wiring-question

[65 Cobra Dude]

Thanks for the clarification and link Paul. It does work perfectly.

Thx,

Henry