dmclaren

Hi guys,

I have a 2008 M5 LCI and I'm usually on M5board. You guys seem more tuned into the general E60 mods, so maybe you can help me. My goal is to get swap the incandescent bulbs in the taillight bulb carrier to LEDs.

Hope you won't mind me reposting my question from M5 board:

I already have a 2008 car, so I don't need an LCI taillight conversion. However, I'd like to know if the plug that goes into the taillight bulb carrier is the same type and pinout for both LCI and the older taillights.

Here's the reason: I've got the bulb carrier out and thinking about how I might attack LED bulb swaps for the incandescent bulbs. There are three 1057 bulbs, two behind the LCI lamp (we have Celis in the E39 world; maybe it's the same technology?), one for the round area, and one wedge bulb for reverse which at a glance looks like T10 but I'll verify that.

What I'm thinking to do is fab a small board to mount resistors, with the board mounted outside the lamp assembly to keep the heat from the resistors away from the plastic. For bulbs that are on solid, not flashing like turn signals, the resistors will build up a fair amount of heat just like a light bulb so they should not be mounted on plastic. A separate board should take care of the heat management.

Managing the wiring for the resistors is the issue. I could drill holes through the bulb carriers and run leads through them and solder them to the traces going to the bulbs, then gather the leads and tie wrap them into a simple harness which would go to the board. That would certainly work, but it's not clean. So, I'm thinking that if I buy some LCI retrofit cables, I'll have one female and one male connector. My idea is to have the stock harness plug into a new female connector, the leads going to the resistor board, then leads from the board terminate in a male connector and plug into the bulb carrier as normal. This way, it's totally reversible by simply unplugging the resistor board, plugging the harness back into the bulb carrier, and reinstalling the incandescent bulbs.

Recap of the main question: Do pre-LCI and LCI taillights have the same connector? If so, my plan should work fine. Still need to dial in the right resistors and LED bulbs, but that's pretty easy.

Thanks for any guidance.

Dave

PS. Thanks to nixdorf and Andy545 for the front turn signal mod. I still got error messages, but not the nagging in-your-face ones that keep popping up while I drive. I think the problem is that I used 10ohm resistors I had around from my E30 325iC turbo project which has all LED except for the rear running lights which look better stock. Seems to me that 10ohm resistors have too much resistance, so the OBC isn't 100% sure what is going on, whether it thinks the bulbs are really out or not. I just received some 6ohm resistors which I'll install this weekend. That'll probably take care of it. If not, I'll try running two resistors in parallel to cut the resistance in half, narrowing the discrepancy in resistance to get closer to the resistance of the stock bulb. BTW, I'm running 5 SMD LED lamps in the side indicators. I had to shave down the base a bit, but I got them in and they work great.

nomis_nehc

Oh man, you're making this way more than it needs to be.

Just get the LEDs and swap them out, come to me and get the car coded -- voila, no need for resistors.

I have not heard of anyone "wanting" to go through so much work to swap to LEDs, lol.

Additionally, PM me if you're interested in doing other mods I offer as a service as well.

dmclaren

Wait, so you can code it so the OBC isn't looking for resistance through the bulb filaments? Basically, it just takes that off the 'ol checklist?

Dave