Alex99

Hi,
yesterday I switched to the Euro taillights on my 2000 C5 and substituted the red tail/brake portion with LED bulbs.
Everything seems to work OK, but now the third brake light is illuminated when I switch on the lights. It stays on when I apply the brakes.
I've read that there might be ground problems or issues with the Euro harness.
Where is the correct ground location that I would need to check?
Any other hints on what this could be?
I've cut he white wire under the dash.
The turn signal still have conventional bulbs.
Thanks
Alex

Alex99

UPDATE:
I just tried putting the original incandescent bulbs back in and everything worked fine. With the lights on, once I plugged in one LED bulb, the CHMSL (third brake light) lit up and never stopped while I was putting the rest of the brake/tail LED bulbs in.
I thought the CHMSL and taillights are on separate circuits that have nothing to do withe each other? I guess I was wrong.
Any thoughts?

TheWildcat

I have a couple rear std harnesses if you need one..John

Blue Blood

It might have something to do with the lower voltage consumption by the LED's, similar to the hyper flash on turn signals when the LED lights are used.

LoneStarFRC

Well, the CHML does come on with the brake lights of course but must not flash when the turn signals are on, so it has to be isolated from the turn signals in that regard only. The turn signal actuator circuit design determines when and under what circumstances it gets power.

Alex99

For clarification: the turnsignal operation is ok with and without the LED bulbs in the red portion of the Euro lights.
Its the red taillight portion that seems to be affecting the CHMSL operation. When I turn on the light switch I get four taillights and the CHMSL illuminated. If I step on the brake then, the four reds continue to be illuminated but with higher intensity, just as supposed to be.
I also cleaned all ground points in the rear of the vehicle. Didn't change anything.
I also thought about the electroninc flasher module, but I don't understand its connection with the CHMSL.

Blue Blood

Yeah, I don't either, it was just a guess. It sounds like it's related to the LED's though. I would PM TSTAR, or RadioFlyer, and see if they can help.

MyVetteDream

Hi Alex! I don't remember ever having this issue, but I agree with Blood... it's related to the lower voltage.

I have LED's in my SRT interior and one of them stays on --- just a little, not full intensity. But nonetheless, it stays on. I switched the bulb and still the same.

I'm not an electrical engineer, but could your LED's cause some kind of "electrical bleeding", making your 3rd light glow?

olefam

Hi. I have the exact same set-up - euro lense, LED bulbs. My car came from the factory with the Euro wiring harness and factory lights. When I tried LED switchbacks in front I had problems with them not switching. I then went with just amber LEDs and all is well. The point is, your problem is probably minor, you just have to track it down. To help you with that, no one I've spoken or written to has more knowledge of LED lighting than Jonathan at JWM. You might try to give him a call to see what he thinks.
Just a thought...
Glen

Alex99

The story continues: I have tried to put back the LEDs into the tail/brake portion of the lamp and connected the 3rd brake light directly into the brake circuit (where I could actually see the connection) - the problem still exists. The 3rd brake light lights up once I switch on the driving light.
Since I didn't had enough time to build back to the incandescent bulbs I just disconnected the 3rd brake light and drove the car to work. Well, now the Cruise control function stopped working.
I also have the feeling that the LEDs lower load is disturbing some functions but I am shocked how this minor bulb change has an effect on totally unrelated systems of the vehicle.
I'm not quite sure what to do next to figure out where the problem comes from.
Does anyone has a wiring schematic from a US-spec 2000 C5?
Thanks
Alex