Paging Silverstreak98

[Beergoggles]

I bought the inpro led taillights and superbrightled resistors from your GB (thanks again for organizing that!). My question is how did you wire up the resistors?

On the running/brake light section (thats where the resistor gets hooked up to, right?), I have a Black, Green and Green/White wire. I guess one end of the resistors goes to the black, but im not sure about the Green and Green/White.

[EuroDriven]

I am deff an electronics person, so I will try to help here.

I am not 100% on any of this but about 98% sure :P (cliff notes at the bottom)

Since you are using LEDs, they use less power then the incandescent bulbs on the cars did, and since our cars will have a service light for a blown bulb you need to make sure you load whatever is driving the bulb to make it "look" the same.

Since you stated this is a running/brake light, I will go ahead and use logic here and say that the black wire is ground, the green is power (positive), and the green/white is power as well. This is a two function light, brake and running light so there are two modes, brake light on, or running light on (or both but that is same as brake light on, or all off, but thats obivous). To be able to have the same load for both modes of operation you need to put the resistor in series with the black wire.

How this works is, the black wire should ALWAYS be negative, basically if you take a multimeter and connect one lead to the black wire, and one lead to the battery+ you should always get a voltage reading. The green and green/white wire are switched signals, if you put a multimeter between the black and green or black and green/white you should only see voltage on them when one of the lights are on. So if you put the resistor in series with the black wire, you should have the same load for either mode.

Cliff notes:
cut the black wire, put one side of the resistor to one side of the black wire, and put the other side to the other side of the black wire.

[theoretically even if you put the resistor in the wrong spot, or not in at all, the lights should still work, the car will just have the service light one]

Someone confirm this as these lights may require a specific application.

[Beergoggles]

Thanks John. Right, the lights work without the resistor. I guess i can check with a multimeter when I get home from work. So I take it, one of the lines (grn or grn/white) shouldnt have power when just the running lights are on. That would determine the brake wire I want to tap the resistor (+) into?

[EuroDriven]

Yes. But if the whole tail light is LED I would assume you would want the resistor on the ground wire. (This all depends on application here) Things can make this different, the amount of LEDs changes the load so the resistor values between the 2 could make it different.

I am not sure why you want to put the resistor on the green or green/white wire. Not to say you are wrong, but like I said it is all application. Do you have 2 resistors? Do you only need the extra load for 1 mode? Does the service light only look at brake/signals? (<< I don't know why they would save the couple cents to not put it on running lights though)

For example, if the running lights (less bright) use X power, then the brake lights could use 2x power (lets just use an integer to keep it simple). Your stock lights could use 10X power. This means to see the "load" your running lights could need something to use the extra 9X power for the running lights, and something to use 8X power for the brake lights. So like I said it could need 2 resistor values, one on each power wire (green and green/white)

Going off the same example as above, if there is some tolerance built into the system, then you could use something to use the extra 9x power and put it on the ground wire. This will still make it look like an acceptable load the ECU. This means it will see 11X load for the brake like, and 10X load for the running lights.

But, just to not cause confusion, there are also different ways the light could be wired internally. If the SAME LEDs are used for each mode and the brightness changes, then if you have the running lights on AND the brake lights, the the LEDs are still using only 2X power. If there are individual LEDs for each mode then it would use 3X power when both are on, and therefore 12X power if a single resistor is on the ground wire (still acceptable pending any tolerances or what not).

You can also try looking at the specs for everything. If you have a multimeter with a current function (denoted by a mA usually) then you could measure the current in each mode, and find the wattage of each mode of the original lights (with incandescent bulbs). If you do this then you could figure out how to wire it. If you post the currents and voltages here for each mode of each light I can help you figure out what resistors are needed.

Basically though just as an FYI, there is basically no way to break your taillights. I would assume they work without the resistors, which you have stated is true, so no worry there. If you hook the light up with reverse polarity then still nothing wrong, the LEDs are DIODES and only allow current flow in 1 direction. If you choose a resistor value too small, well this is impossible, as no resistor works fine, and you can't have a negative resistor. If you choose a resistor too big then your lights just aren't bright enough.

Good luck, let me know how it works out.

-John

[Beergoggles]

Ok, will do. Ill probably do it this weekend. Ill try to track down my camera and take pics.

[Mawhitey]

The lights will 100% work without the resistors. However as soon as you turn the lights on or brake the DIS will illuminate to say a bulb failure due to the lack of current consumption from the LEDs compared to a "normal" bulb