[redlaxin18]

I wanted to convert the flip down ash tray in my wj into a switch panel for my rack lights and a few other accessories but... i'm not exactly a master of wiring. I built the panel and wanted to have leds mounted above the switches as opposed to using led switches. I was just hoping that somebody could tell me what i need to do/how i need to wire the switches to the leds so the leds turn on when the switches are on. I've already been told i'll need resistors so i went ahead and calculated which ones i need using a formula someone gave me. Also wondering how to wire this into the relays for my daylighters.

What i've got so far

 

[Jeepy5Point2]

ok since you already know what resistor you need here is a diagram of how to do it... (this is set for each switch and led set to be seperate form all the rest)

i might have the 87 and 87a backward just pay attention to the position i know that is right. anyway i should listin to my own advice and get bigger relays but you should problay use a large relay for the lights, i have 2 55 watt lights nothing special running on a 40 amp and never have had a problem, but i wouldnt do more than that, if you have more i would do 2 sets and i would run a seperate relay for each if they are more powerful

here is the first site i cam across for relays, but your can pick them up at napa too http://www.keefeperformance.com/kprelay.html

good luck that looks like a cool setup let me know if you have any other questions

 

[redlaxin18]

Thanks for the help. I was already planning on running each pair of my lights on their own relay. I've got 4 questions for you.

1) It appears from your diagram that i should splice a wire off the ground for the switch and go to the led with it then splice another wire off the lights power and run that to the other side of the led. Correct?

2) What exactly is going on between 86 and 30 on the relay in your diagram?

3) To your knowledge... Will wiring the leds into my light system make my lights any dimmer?

4) The formula i got for the resistors basically stated that i take the total voltage of the power source and subtract the typical voltage of the leds then divide that total by the amperage of the leds. That gave me 515 ohms for the red and 495 ohms for the green. Is this formula correct?

 

[Jeepy5Point2]

glad i could help, usually i am the one asking for help on here, but i can hold my own in this section

1) yes, the input for the switch is ground ( you want as little 12volt wires in that area as possible because it is going to get very cramped very fast ), and that ground wire will also link over to the led..

one note you can use the same ground input for each switch, just loop all the inputs together as well as the ground for the leds

the out put of the relay that is going to send the 12 volts to your lights will also at the same time send the 12 volts to your led but make sure the resistor is in that path.

2) 30 is the typical input for a relay so you are going to have your 12 volt source going into that. for a realy to work it needs a ground input (85) and a 12 volt input (86). since you will be using the ground as the switch you will jump the 86 and 30 together to have a constant 12votl source. it will not use any of your battery power when the switch is off. when it is off the 30 and the 87a are connected, when powered on the 30 and the 87 are connected.

3) no not at all, the leds will use so little power that it doesnt even matter. you could used small 12 volt light bulbs and it wouldnt make any difference. the biggest thing you need to do is make sure you use the proper gauge wire to power your ligths. i have a 8 guage power and ground runnign to my 2 55 watt lights and a 10 guage power and ground going to my smaller 35 watt reverse lights. power are tsunami amp wire from circuit city if you want to compaire.

4) it appears your calculation is correct, to put it more technically and complicated i posted this when i did my writeup on the electric fan mod...

The calculation used to find the value of the series resistor we need to know the diode forward voltage and current and its connections.
This information can be obtained from the package if you purchased the LED.
In this example it is 2 volts and 20mA (0.02 amps).
The cathode lead is the one nearest a "flat" on the body.
Since the voltage across the diode (LED) is 2 volts and the battery voltage is 12 volts, then the voltage across the resistor is 12-2 = 10 volts.
The diode is in series with the resistor, so the current through then both is the same, 0.02 amps.
We now know the voltage across, and the current through the resistor.
From Ohm's Law we can now calculate the value of the resistor.
Resistance = Volts divided by Amps = V/I = 10/0.02 =500 ohms.
Since this is not a standard value we can use a 470 or 560 ohm resistor as this application is not critical of values.
For a 4 volt (Blue or White LED) the formula would be:
Resistance = Volts divided by Amps = V/I = 8/0.02 =400 ohms.
The common 390 or 470 ohm resistor can be used for these.

 

[redlaxin18]

Does the wire going to the leds still need to be 8 or 10 guage or can it be smaller?

 

[Jeepy5Point2]

no it can be very small, i would try to get some really cheap speaker wire, it is usually like 20 to 24 guage, it doesnt need anything at all...

you can either put both wired into a crimp cap that go onto the relay or just strip back the 8 guage and tap the smaller wire to that. either way will work fine


also the ground wires can all be small (except for the where you ground your lights that has to be the same size as your power so in this case 8 guage)

but all the switch wires and led wires and also the 12volt jumper between 30 and 86 can all be small. i would use 18 guage wire for all of that.

 

[CustomCreations]

Do you know what voltage og LED's you bought? By saying you did a calculation I assume they are eith 1.5V or 3.3 V leds. I know you can get 12V leds so wanted to check on that. Otherwise the wiring diagram provided looks right and the switch panel looks great. Be sure to include pics when it is installed and wired.

 

[redlaxin18]

Alright thanks for all the help you guys... I'm gonna try and get the switches ready over the weekend and my lights and rack arrive on monday or tuesday so i guess i'll post pics up by the end of next week. Once again thanks so much for the help jeepy.

Luke