Discussion
Hi all,
I got myself a rain light with the intention of installing it on the crossbars of my Roll bar as a brake light.
http://www.demon-tweeks.co.uk/motorsport/rain-ligh...
The light was delivered with two small resistors.
Are these needed or can i just connect the two wires of the led lights on the wiring of the brake lights?
Thanks
I got myself a rain light with the intention of installing it on the crossbars of my Roll bar as a brake light.
http://www.demon-tweeks.co.uk/motorsport/rain-ligh...
The light was delivered with two small resistors.
Are these needed or can i just connect the two wires of the led lights on the wiring of the brake lights?
Thanks
Hi;
The web page the OP linked to has instructions on it; something like, "the two resistors with the light must be wired in series to the red wire, and the white wire to ground."
LED lights use resistors for a few reasons; first, in more sophisticated cars, to ensure there is enough load on the circuit to keep the computers monitoring lights happy. Second, to keep non-LED friendly flashers for turn signals flashing at the same sane speed if LEDs are used instead of bulbs. Third, to decrease brightness of LEDs to a safe/legal/tolerable level.
I did the same trick with a rectangular FIA rain light, using it as a third brake light, and I had to put quite a resistor in it to make it more a brake light than a solar flare. :-D
The OP may find he needs a third resistor to keep his brake light more a brake light than a fog light in brightness, though YMMV of course. Some people use a, um, drat, can't remember the name... but a dial that changes resistance across the poles, so they can tune it to exactly what they want, if they have room to put that somewhere. You could mount one inside the boot, on the side.
The web page the OP linked to has instructions on it; something like, "the two resistors with the light must be wired in series to the red wire, and the white wire to ground."
LED lights use resistors for a few reasons; first, in more sophisticated cars, to ensure there is enough load on the circuit to keep the computers monitoring lights happy. Second, to keep non-LED friendly flashers for turn signals flashing at the same sane speed if LEDs are used instead of bulbs. Third, to decrease brightness of LEDs to a safe/legal/tolerable level.
I did the same trick with a rectangular FIA rain light, using it as a third brake light, and I had to put quite a resistor in it to make it more a brake light than a solar flare. :-D
The OP may find he needs a third resistor to keep his brake light more a brake light than a fog light in brightness, though YMMV of course. Some people use a, um, drat, can't remember the name... but a dial that changes resistance across the poles, so they can tune it to exactly what they want, if they have room to put that somewhere. You could mount one inside the boot, on the side.
Edited by Canuck7 on Saturday 10th June 06:44
Excuse the most stupid of questions but i am not sure i know how to connect the rain light to serve the purpose of a third brake light.
I mean, which wire of the right side rear loom is the one of the brake light.
My right rear light loom consist of:
Black wire (i assume earth??)
Red wire
Green wire
Green/blue
One of the above should be connect to the two resistors then to the red wire of the rain light, whereas the black wire of the rain light should be connected to the earth wire of the rear light loom, correct?
Cheers
I mean, which wire of the right side rear loom is the one of the brake light.
My right rear light loom consist of:
Black wire (i assume earth??)
Red wire
Green wire
Green/blue
One of the above should be connect to the two resistors then to the red wire of the rain light, whereas the black wire of the rain light should be connected to the earth wire of the rear light loom, correct?
Cheers
Ah... good question. The full instruction vs. what wire does what at just the LED rain light. :-)
I can't tell you specifics for wire colour, because it's been a few years (and the cars may change over time) - but it is easy to figure it out for yourself.
You can take the lens off the rear light, and see which two wires go into the "red" bulb. One of those will be the running light, one will be the brake light wire. If you take the bulb out, and use a circuit tester of some sort; either a voltage meter or a bulb and two bits of wire, you can find which connector in the bulb holder is "on" when the car's lights are on. The other must be the brake light wire. So that's pretty quick and not too much hassle to determine.
After you know the wire and its colour scheme, you can use a vampire tap or something better, to splice into it under the wheel fender (wrap it in electrical tape after), and run that wire up into the boot and onto the roll bar, and put the two resistors in series with it to the rain light.
For a ground, you just need to run the ground wire to any nearby decent bolt that makes good metal contact. The whole frame and panels of the car are a ground. I used the bolt that is beside the base of the roll bar, and helps hold it in place. I crimped on a wire fitting for connecting to bolts. Taped it all up, hiding the wire against the inside of the roll bar, and then put SFI approved impact absorbing rollbar foam over top of it all.
The hardest part was creating a respectable clamp to hold the light to the rollbar, and not use the cheapo P-Clip. :-)
When you think you have it all correct, have someone push the brake pedal for you and check if it works before making it all permanent, and also check for suitable brightness and any overheating wires or resistors. The resistors can get quite hot if not burly enough.
I hope that helps a bit more.
I can't tell you specifics for wire colour, because it's been a few years (and the cars may change over time) - but it is easy to figure it out for yourself.
You can take the lens off the rear light, and see which two wires go into the "red" bulb. One of those will be the running light, one will be the brake light wire. If you take the bulb out, and use a circuit tester of some sort; either a voltage meter or a bulb and two bits of wire, you can find which connector in the bulb holder is "on" when the car's lights are on. The other must be the brake light wire. So that's pretty quick and not too much hassle to determine.
After you know the wire and its colour scheme, you can use a vampire tap or something better, to splice into it under the wheel fender (wrap it in electrical tape after), and run that wire up into the boot and onto the roll bar, and put the two resistors in series with it to the rain light.
For a ground, you just need to run the ground wire to any nearby decent bolt that makes good metal contact. The whole frame and panels of the car are a ground. I used the bolt that is beside the base of the roll bar, and helps hold it in place. I crimped on a wire fitting for connecting to bolts. Taped it all up, hiding the wire against the inside of the roll bar, and then put SFI approved impact absorbing rollbar foam over top of it all.
The hardest part was creating a respectable clamp to hold the light to the rollbar, and not use the cheapo P-Clip. :-)
When you think you have it all correct, have someone push the brake pedal for you and check if it works before making it all permanent, and also check for suitable brightness and any overheating wires or resistors. The resistors can get quite hot if not burly enough.
I hope that helps a bit more.
I made a mount for the same light you've linked to.
Just to give you another option, I found the cross in the rollbar a little low, and made mounting the light a bit awkward (I could also see it in the rear view mirror which got on my nerves a bit!).
I made a small mount out of acrylic that bolts through the holds at the top of the rollbar. It's intentionally placed so that it's visible through the half hood and above any boot bag that's fitted. Since it's lower than the bar, it doesn't get in the way of the full hood either, but it's still too high up to see in the rear view mirror.
The resistor is hidden in the little box mounted on the other side of the acrylic, which is weather proof, but still accessible if I need to change any parts.
https://goo.gl/photos/aqNcFTuVNX7rztwr8
https://goo.gl/photos/ZR9Y3n8YpAnJyGAEA
I made a prototype out of cardboard first just to get the fit right before cutting it was acrylic.
https://goo.gl/photos/FYk2setngwA8cWSs5
Just to give you another option, I found the cross in the rollbar a little low, and made mounting the light a bit awkward (I could also see it in the rear view mirror which got on my nerves a bit!).
I made a small mount out of acrylic that bolts through the holds at the top of the rollbar. It's intentionally placed so that it's visible through the half hood and above any boot bag that's fitted. Since it's lower than the bar, it doesn't get in the way of the full hood either, but it's still too high up to see in the rear view mirror.
The resistor is hidden in the little box mounted on the other side of the acrylic, which is weather proof, but still accessible if I need to change any parts.
https://goo.gl/photos/aqNcFTuVNX7rztwr8
https://goo.gl/photos/ZR9Y3n8YpAnJyGAEA
I made a prototype out of cardboard first just to get the fit right before cutting it was acrylic.
https://goo.gl/photos/FYk2setngwA8cWSs5
Canuck7 said:
Ah... good question. The full instruction vs. what wire does what at just the LED rain light. :-)
I can't tell you specifics for wire colour, because it's been a few years (and the cars may change over time) - but it is easy to figure it out for yourself.
You can take the lens off the rear light, and see which two wires go into the "red" bulb. One of those will be the running light, one will be the brake light wire. If you take the bulb out, and use a circuit tester of some sort; either a voltage meter or a bulb and two bits of wire, you can find which connector in the bulb holder is "on" when the car's lights are on. The other must be the brake light wire. So that's pretty quick and not too much hassle to determine.
After you know the wire and its colour scheme, you can use a vampire tap or something better, to splice into it under the wheel fender (wrap it in electrical tape after), and run that wire up into the boot and onto the roll bar, and put the two resistors in series with it to the rain light.
For a ground, you just need to run the ground wire to any nearby decent bolt that makes good metal contact. The whole frame and panels of the car are a ground. I used the bolt that is beside the base of the roll bar, and helps hold it in place. I crimped on a wire fitting for connecting to bolts. Taped it all up, hiding the wire against the inside of the roll bar, and then put SFI approved impact absorbing rollbar foam over top of it all.
The hardest part was creating a respectable clamp to hold the light to the rollbar, and not use the cheapo P-Clip. :-)
When you think you have it all correct, have someone push the brake pedal for you and check if it works before making it all permanent, and also check for suitable brightness and any overheating wires or resistors. The resistors can get quite hot if not burly enough.
I hope that helps a bit more.
You were right,I can't tell you specifics for wire colour, because it's been a few years (and the cars may change over time) - but it is easy to figure it out for yourself.
You can take the lens off the rear light, and see which two wires go into the "red" bulb. One of those will be the running light, one will be the brake light wire. If you take the bulb out, and use a circuit tester of some sort; either a voltage meter or a bulb and two bits of wire, you can find which connector in the bulb holder is "on" when the car's lights are on. The other must be the brake light wire. So that's pretty quick and not too much hassle to determine.
After you know the wire and its colour scheme, you can use a vampire tap or something better, to splice into it under the wheel fender (wrap it in electrical tape after), and run that wire up into the boot and onto the roll bar, and put the two resistors in series with it to the rain light.
For a ground, you just need to run the ground wire to any nearby decent bolt that makes good metal contact. The whole frame and panels of the car are a ground. I used the bolt that is beside the base of the roll bar, and helps hold it in place. I crimped on a wire fitting for connecting to bolts. Taped it all up, hiding the wire against the inside of the roll bar, and then put SFI approved impact absorbing rollbar foam over top of it all.
The hardest part was creating a respectable clamp to hold the light to the rollbar, and not use the cheapo P-Clip. :-)
When you think you have it all correct, have someone push the brake pedal for you and check if it works before making it all permanent, and also check for suitable brightness and any overheating wires or resistors. The resistors can get quite hot if not burly enough.
I hope that helps a bit more.
After checking the wires and the connections the light is now on
However i didnt like the intensity with the two resistors in series which i now removed and is not much much stronger.
Since i mainly drive the car in the day i prefer it to be this way and make sure their all know when i am on the brakes, either still in traffic or decelerating.
Thank you gentlemen
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