just did this to the exact thing but it doesnt work, once i plug it back in the low bean lights comes on BMW E30 Independent Fog Lights
he saids. and i even try it and nothing.
Use care when installing K4 because I ran into a issue by pushing forcefully down on the relay, where the low beams came on and stayed on even w/ the keys removed from the ignition. I'm guessing the extra wiring I soldered was pushing up on the base of the relay, causing the internal contacts to touch and engage the low beams. I simply backed off on the install pressure and everything has been fine. Turn on the parking lights + fog switch and enjoy the results."