Hey guys I have an 03 f4i and am missing the headlight harness. I plan on splicing behind the big grey connector and just hardwiring it. I am using an aftermarket headlight and stock horn. I pulled up some diagrams but they show a headlight relay so before I get started Im asking for some advice. I also need to wire the horn so if someone can point me in the direction of where those wires are as well it would be appreciated. Thanks.

 

I would recommend running a relay for your headlight. It's high current would wear out your switching contacts too quickly.

Your best bet is to look at your wiring diagram and try not to stray too far from the original unless you believe you are brighter than the original engineers

 

just go with the diagrams you got, Sparky88 is right about a relay too