DRL Removal (The proper way)

[guibo09]

Yes, i know that BMW grounded the circuit, but im trying to figure out where they grounded it out to.

one question for you though, when you push in your switch, do all the dash light go out? or do they stay on as well along with your low beams?

my dash lights are always on no matter what position the switch is on. its one of the most annoying things about DRL

[iignite]

well then how does this low beam relay affect everything else then?

ughhh..... ive been looking at schematics for a couple of hours now.... i dont know what to do....

[SamE30e]

my dash lights are always on no matter what position the switch is on. its one of the most annoying things about DRL

Mine never were, thats weird. It seems like they did things a couple ways.

[iignite]

it was verified that the DRL's werent affected from the light switch right?

[SamE30e]

Mine weren't and my buddies weren't. But I've only seen 2 cars with DRL's.

[guibo09]

me neither, no switch in the car affects the lows.

[iignite]

i think we are back to square onee...

[guibo09]

i think we are back to square onee...

why is that? you cant find the ground for the low beam relay?

[MattM]

im so lucky, my car is 84 and never had it... :)

[iignite]

well in sams case, im assuming everything worked like US spec cars including the proper functions of the interior lights (1st pos: everything off, 2nd pos: parking lights n interior, etc) but just his low beams were on all the time.

In our case, the wiring itself is all fucked up. The interior along with other things are always on. So that should mean that its not only this relay that was checked out. Sure, we can cut the wire from the relay to the switch, but that wouldnt result in the interior and parking lamps to work correctly.

[bimmer_E30]

My Dashboard lights stay on all the time, i don't even use the switch anymore, i hate it. is there is a way i could get rid of the whole system for once? god i hate this so much. maybe a fuse?

[bignslow]

I figured out how to do this on 90-91. Will be posting details and wiring diagrams in a bit.

[bignslow]

So here is the deal with 90-91 models. There is no magic ground wire like older models. It's a combination of wiring, relays and a different headlight switch. After searching for Canadian specific wiring diagram I came up empty and had to trace some of my wiring. Luckily all of it is under the dash and isolated to 3 relays that will need to be removed and 2 connectors. Headlight switch and C103.

With DRL cars the headlight switch is pretty much entirely bypassed. The switch itself doesn't even have internal circuitry to allow you to turn on the headlights, only parking lights.

There are 3 relays under the dash on the driver side. They are responsible for controlling DRLs and headlight behavior. If you just pull the relays you will lose your headlights completely. What needs to be done is elimination of the relays and returning all wiring to non DRL spec. It's not very difficult.




There are 4 wires on headlight switch and C103 connector that will need to be clipped at the relays and joined back together according to the diagrams. I used solder and heatshink tubing. If you find a US car I would imagine you can just snag the 4 wires from headlight switch to C103 and replace them with yours. That way it looks factory and no cutting or splicing.

There is also a new wire that needs to be added to pin 1 of the headlight switch for cluster illumination.

The yellow/green wire on pin 11 of headlight switch will connect to C202 which is a white connector on top of the steering column. This wire will need to be spliced with pin 11 on C103.

Here are a couple of diagrams showing what changes need to be made.








This is the wire that needs to be added to pin 1 on the headlight switch and attached to existing illumination wiring. When you remove the relays there will be a spare gray/red wire that this can attach to.




Relays removed. There will be 2 or 3 wires (can't remember) attached to the relays that will go into the main harness. I think 2 are grounds and 1 attached to a diode. They can be clipped and removed entirely.




The only thing left to do after this is replace the headlight switch with non Canadian version. I have confirmed that there are 2 different switches. If you leave Canadian switch in there you won't have any parking lights or tail lights when the headlights are on.

Canadian cars have option L838A. Switch with part number 61311386631.

What you want to replace it with is 61311377281.


I ripped apart my old switch for testing and to find out what's different. There are actually contact traces that are missing.




I soldered some traces for testing and confirmed that it works. I believe that is what's different inside the USDM switch.

[TwinScroll]

Hey, thanks for this. I just had a major wire wipeout behind the relays and I rewired everything. I missed this part but I think I'll tackle it later as a fall project.

When I did rewire I noticed my headlughts came on all the time but no dash or parking lights at position 0. Position 1 turned on parking and dash lights, so everything. And position 2 was like 1. I checked all the relays and the white one clicked by there was no resistance, maybe that's why no dash lights at position 0. I don't mind this as its true DRL. But I have city lights and the effect isn't as good when there are no headlights. I do like that there are no dash or parking lights at position 0.