Anyone tried the GE Nighthawk LED headlights in the C4?

[Darrin kirby]

I installed them yesterday. Man, what a difference! Bright, clean, great dispersion. I think I have them aimed a bit low in fact, but still WAY better than stock.

I do have to make a minor mod to the driving light ground to get them working (they're grounded through the high beam filament...LEDs don't have filaments!). Minor stuff.

They're pricey, but still way cheaper and less painful than a proper HID conversion.

 

[2KforeverC5]

Just replaced mine with Sylvania. Sale at Triangle. Now the pop ups stayed up. Have to fix. (2000 C5 Coupe)

 

[OL Yeller]

Just replaced mine with Sylvania. Sale at Triangle. Now the pop ups stayed up. Have to fix. (2000 C5 Coupe)

That might have something to do with the way the harnesses are plugged in. I was told that if that happened, one of the light harnesses had to be turned around and it would work fine. Something about polarity (whatever that is, i'm no electrician) that being said, mine are still sitting on the bench in the garage, I will try again this season when I get some free time.

 

[2KforeverC5]

That might have something to do with the way the harnesses are plugged in. I was told that if that happened, one of the light harnesses had to be turned around and it would work fine. Something about polarity (whatever that is, i'm no electrician) that being said, mine are still sitting on the bench in the garage, I will try again this season when I get some free time.

Thanks. I'll check it out. I did have some difficulty on the passenger side. Have to take the whole head light just to make the exact fit. I might have to do the same on the driver side. Thanks again.

 

[2KforeverC5]

Thanks> I'll check it out.

 

[2KforeverC5]

Did all that and the POP UP remains open. The low beam LED flickers even when off. Next project. Will be putting the halogens back hopefully everything returns to normal. It would have been nice if those LEDs cooperated. Any further suggestions will be appreciated. Darrin mentioned about a ground filament from the high beam. I just wonder what that is.

 

[OL Yeller]

That's the same outcome that I ended up with, lights flickering and pop-ups wouldn't close up. After installing and removing the lights the 3rd time, I left them on the bench.

 

[2KforeverC5]

I installed them yesterday. Man, what a difference! Bright, clean, great dispersion. I think I have them aimed a bit low in fact, but still WAY better than stock.

I do have to make a minor mod to the driving light ground to get them working (they're grounded through the high beam filament...LEDs don't have filaments!). Minor stuff.

They're pricey, but still way cheaper and less painful than a proper HID conversion.

How did you modify the driving light grounds? Interesting. Share please. Thanks

 

[Darrin kirby]

Here's the write up taken from a review/how-to regarding installing Nighthawk LEDs in a C4. Unfortunately, I don't have the link to the original article.

The second part of the Nighthawk LED installation on a C4 is a modification to the fog light wiring behind the right-hand side of the dashboard. C4 fog lights are grounded through the high-beam headlamp filaments. When the fog light switch is on and the low-beams are selected, current flows through the fog lamp relay coil then, through the high-beam circuit to ground. That energizes the relay and the fog lights come on. When the high-beams are selected, voltage on both sides of the relay control circuit is equal, and current won’t flow. The relay is de-energized so, no current flows to the fog lamps, even if their switch is on. This system will not work when Nighthawk LEDs replace stock headlamps because the LED’s have no filaments.

The modification to the fog lamp wiring requires the light green wire coming out of the fog lamp relay be grounded directly to the chassis rather than through the high-beam headlamps. The relay is located behind the trim at the bottom right side of the dashboard in the relay retainer. You will need to remove the lower right-hand trim panel and the knee bolster which is behind it to gain access to the relay wiring. There are four, or, if it’s a ZR-1, five relays there and the fog lamp relay is front row, far right. Four wires will connect to it: yellow, light green, purple and brown. Find the light green wire and cut it and splice in a new section which grounds to the chassis. This will restore fog lamp function when the headlight are on low-beam and allow the fog lamps to be on when the high-beams are on as well as when the low-beams are on.