Patrick - LED Taillight problems

[Xack]

Originally Posted by DanEC

I think it is some sort of cross-talk issue through the flasher, turn signal or trailer relay unit. That it's picking up the license plate lamp and flashing it is also wierd. About the only thing these 3 cirucuits have in common is the battery and grounding through the frame to the drivetrain.

So, you are suggesting to remove one of the four 1157 bulbs and try the turn signals and brakes to see what I have on the remaining 3 bulbs? Or jumper the power and ground at the removed bulb socket?

If you have the system with just incandescent bulbs, No LED's at all. Take a bulb out as if it's "blown" and see how the system operates. Will it do anything strange? No jumper anything at all.

The unplugging will help you see what acts normal when you isolate parts of your system by pulling bulbs out... However, your blinker circuits depends on a load for the flasher to work. When you take out the bulb, I would expect that side to not blink properly. The other side should work OK. This pulling the marker light bulb will check behavior for the marker light circuit only. Now, having said that, it may show something misbehaving and you can do these bulbs to try and isolate the problem.

I would suggest after all that and see if strangeness persists, to connect the ground on the offending bulbs to the battery ground or as close to it as possible. You can just put your VOM on ground at bulb and ground at battery to see if it goes up by any measure from 0 Volts to + something to drive a light on. Jumping the ground at the bulb should allow you to isolate issues surrounding grounding.