Thread: Turn signal help.. when lights are off, ALL corners flash when turn signal on..

2008 Grand Prix GXP
Perplexing issue. Hoping that someone can help out. I've done a search of this forum as well as the internet and haven't come across anything conclusive.

About 2 weeks ago, I replaced my front and rear turn signals with LEDs from V-LEDS. I forgot to order the load resistors. When the lights were off, (only DRL on when driving), I'd turn on the turn signal and all 4 would flash.. no hyperflash.. the side that I'd selected was brighter, however. Like this video (left turn signal on):

http://1drv.ms/1wcI9r6

When I turned the lights (or fog lights) on, the turn signal would hyperflash, but it would be only the side that I was indicating the turn.

Yesterday, I spliced in some load resistors. That fixed the hyperflash, but I am still having the issue with lights off, all 4 lights flash when I turn on a turn signal one way.

In the back, there are 4 bulbs. I did try replacing the top ones (without the resistors) with standard incandescent bulbs to see if that would help, but no dice.

Any thoughts about what may be causing this issue? I've been pulling my hair out over it for the past couple of days. :/

I have to ask... did you try switching the bulbs back?

Replaced with bulbs, same issue. From additional research, seems like it's probably an issue with a ground wire somewhere. Now to find a document showing where these wires are.. fun.

Originally Posted by b4yp

Replaced with bulbs, same issue.

That's what I would've figured - I wish I could make a guess what wire to go looking for (although that doesn't necessarily sound like a ground)

@SomeDudeAtHome: thanks for the suggestion! I'm not sure if it's LED-specific, but I'll see if they have any thoughts. I did pick up a Chilton's manual last night with a wiring diagram but understanding the diagram is one thing and being able to find the stuff is another. Still paging though. This seems like it should be a common problem with a (hopefully) easy fix, but I haven't found it yet. I should really get a scanning tool or something. Chilton's seems to think that is the first step to solving every problem. My Jeep is a lot more straight-forward with stuff when it breaks.

@bobc455: Thanks anyhow. Also, as an added wrinkle (and I didn't know why didn't think to test this earlier) when I step on the brake pedal the front turn signal lights come on about half brightness. So I'm thinking the rear lights is where I should start looking.. I poked around a bit today and wasn't to come to anything conclusive.. other unexpectedly finding the problem with my radio antenna. I can get AM radio stations in clear as anything now.. at least that's progress on one direction.

Originally Posted by SomeDudeAtHome

Try contacting diodedynamics. They're the big LED vendor on here and might be able to offer some help. And for a wiring diagram you could probably pick up a Hanyes manual at Advance or Autozone.

Just wanted to follow-up. Thanks for the tip! I did contact diodedynamics and they were able to get the issue resolved. FWIW, the issue was caused because there wasn't enough resistance on the back bulbs. I added add'l resistors and that cleared the problem up.