resistors ..I had the same issue with led signals

 

i have that much figured out but i dont know what size. i dont think my volt meter is working right.

 

If there was a way to do this and keep it a clean look in the back I would be all over it!

 

im gonna wait for my brother to look at it. He knows much more about this stuff then I do. He tried to explain it to me over the phone and it all went WAY over my head.

 

doublestick tape works perfectly. Just trying to fab up a simple back cover.

 

criket - you have the same bar? hook up a volt meter to it please!

 

just saw this thread... im loving the brain storming you guys got going on! team effort FTW :-)

 

would it really matter the size of the resistor you put on? Or does it need to be?

 

any news?

 

DONE! and it works great.

 

pics?

 

Ok. So I lied. Yes the light works but now the cruise control isnt. I remember seeing something on here about led 3rd brake and cruise not playing nice together. Gotta see if I can find it again.

 

Guess I need to add more resistance to the light? I knew I should of waited before I started liquid-taping stuff.

low_down_xb wrote:
did anyone ever figure out the cruise control problem, i switched mine out for a led board and it made the vsc, trac, and stuff come on, i switched it back to the factory bulb and it fixed it, i work on GM's all day and they guys that are putting in the leds on their trucks are having a lot of problems with the cruise not working, and for some reason it runs through the third brake light, switch it out and it works fine again, for some reason the resistance is wrong and it thinks that the brakes are on, and believe me their not happy about it when you tell them either here is a link to my led tails and there is a link in there for a video clip as well so check it out, and snow i know you already contacted me about your lights.

snowromance wrote:
yes i figured it out. im sorry i should have gotten back to you about it. Just like with turn signal circuits...its the resistance. i mean obviously thats the only difference between LEDs and filament to whatever logic is controlling or overseeing the circuit. You will need to put more resistance like the ones you use in turn signal LEDs in your brake light circuit as well. I havent done this yet but have read from a lot of people with other cars that have and say thats what fixed the problem. It sucks these newer cars are designed to run with filament bulbs but thats just the way it is so we are stuck with having to simulate it with our LED retrofits :-(

 

you guys are killing me.

here... just throw one of these in.


It will fix the "problem" everyone is having.

 

Well. Now isnt this intresting. I have one of those on there already. And the cruise does not work with it. So do I add another one to the light?

 

I looks nice though lol.

 

ok let me get the scenario right again...

you have the sonar LED tail lights, wired in the standard plug&play format (as they come) and have now tried adding this piranha LED 3rd brakelight. right?

I was already running the custom LED 3rd brakelight that i made with 60 lumileds superflux at the time i added the sonar lights and wired them up with my "LED tail light mod". When i first hooked everything up, I had the same problems with the cruise not working, the 3rd brakelight staying partially illuminated at all times, and the warning lights on the dash.

Once i added a set of those resistors i just pictured (because radio shack was part in hand, although i prefer the ones with better heat dissipation) in the manner i showed in the wiring diagram i threw together in the LED tail light mod thread... the problem ceased.

Are you sure you have the resistors wired in correctly? they are in parallel across the positive wire of the brake circuit and main ground wire at each tail light? The computer has to think that your brake circuit has filament bulbs installed for everything to work, to put it simply.

 

Now Im even more confused.

I never had to put a resistor in to get the cruise to work when I put the tails in without the bar. And none of the lights on the dash came on either when I used the cruise. It all just worked.

Personally, I like having separate turn signals from the brake lights, so I haven't done that mod. Thats the only wiring diagram I was able to find.

I have the resistor wired into the 3rd brake light. I havent added anything to the tail lights.

With the resistor in, none of the warning lights came on, and the brake lights, tails or 3rd, were not dim. They were not lit at all until I pressed the pedal. Before without the resistor, the tails were dim but the 3rd wasn't. If the resistor was in right, the lights wouldnt be dim. Right?

What am I not understanding? Sorry for my confusion.

 

I've had no issues with mine, though I have a 2005 with the TYC tails. No cruise control.

 

that is because the filament in the 3rd brakelight was supplying enough resistance to keep things functioning normally.

as a general rule of thumb, i like my turn signals separate too. UNLESS there is no way having a separate set of LEGAL led turn signals. Which in the case of the XB with sonar tails, there's absolutely nothing led you can buy that replaces the turn signal bulb, and is in anyway close to visible enough in daylight. and it's completely illegal/not worth getting put at fault when someone rear ends me. no plug and play bulb off ebay or any other website will work. If you want led turn signals, the led tail light mod is the only way to go if you want bright, legal, led turn signals. Plus it just looks so "factory"

try it again... turn on the cruise control (while parked of course, just push the button on) and the 3rd brakelight will come on dim. That's what was happening to me while i was troubleshooting. The first sentence in this paragraph, describing the results with the resistor in, sounds like normal operation to me. that is what you want to happen.