Let me start by stating this is a method I have devised to suit my needs not duplicate the fatory’s European wiring system. There is a good write up on the M535 registry on how to hook up these lights to work the european way, I suggest you read that post first and make your own decision on which system works for you.
No matter what you decide be assured you will now have far superior lighting than the medieval US sealed beam lights you had. The euro system uses H4 bulbs (unsealed) that can be had in different wattages. The lense also has a unique sharp cut off so light is spread out evenly on the road surface. This may not be new to you since most newer domestic cars have now adopted this technology. US lights usually have a 55 watt low beam filament and a 65 watt high beam. The middle high beam only lights usually have a 55 watt filament. When these lights burn out you have to replace the whole light……with the euro system you just replace the bulb.
Ok just a little more background for those not familiar with the euro system. This is the way they work on european E28s: When you flick your high beams on the center 5 ¾ high beams come on but the 7” low beams stays the same…in low beam mode. The second filament in the bulb is not activated. I guess for some reason engineers thought there will be sufficient lighting in this case. If you have a newer european or domestic car with OEM HID non bi-xenon lights this is also the way they work. I’m not satisfied with this set up.
The US system is something you are familiar with; you flick you high beams and the center high beams come on and then the outer low beams “switch” over to the high beam filament giving you more light! Now I have PIAA extreme white H4 bulbs. (closest product to true HID) The bulb that goes into the 7” lowbeam has two filaments, 80 watts for low beam mode and 110 watts for high but can not untilize the high with the way the wiring harness is set up. This is what I did to get all the watts I paid for.
Most of my modifications were just common sense and not difficult at all. Take the system apart and examine how everything comes together. You will notice the system is very specific and unique to the E28. There are specific locking rings and harness. Pull the boot off the harness and you will see that what is missing is obvious. The female wire connector is missing for the high beam filament. The only wires in the harness are 1) low beam, 2) ground wire, 3) city light.(I didn't include colors of wires in my directions because the harness is pretty self explanatory.) See the picture below:
Here is a picture of a typical H4 bulb. It has 3 prongs and I have labled their role:
Here is a pic of the plug/harness. You can see the wire for the high beam is missing-deleted. We just need to add that in!
I’m sure there are tons of ways to modify the plug but this is the route I choose to make everything look OEM.
1. You will need to take the white plastic base harness connector and drill a hole to accommodate a 16 or 18 gauge wire to power the high beam filament.
2. Pull wire all the way thru and crimp a female connector on the bulb side and male connector to other end.
3. Here is what it looks like on the bulb side.
4. Once a female connector is crimped, push it back into the recessed are of connector. I used electrical epoxy to keep it in place. Make sure it is perfectly even with the other female connectors
You are almost done! Feed the wire right thru the black plug. all the connections of the harness should have male connectors crimped on them and should plug right into the OEM headlight plug. The city light wire should be spliced with the front left parking light + wire so they come on when parking lights are on.
A note on city lights. City lights (Europe & Asia only) are on cars where city law prohibits the use of headlights in city limits at night. Major cities like Tokyo or Berlin are so brightly lit by street lights and neon advertising at night that car headlights are not necessary. City lights basically illuminate the headlight but do not "throw" any light onto the roadway or other drivers/pedestrians. I'm not sure if these laws still apply today but they were in effect at last 10 years ago.
CITY LIGHTS ON- ONLY
HEADLIGHTS AND FOGS ON
FOUR HIGH BEAMS ON - 420 WATTS OF CANDLE POWER!
Hope this was helpful, please let me know if there is anything else I can help with
BEAMTER!!!!!
