Hi, first time posting on this forum, so please let me know if this is in the wrong place or any other issues.
I need your help and advice on fixing an issue with my car (a '99 1.6 s40, very well looked after by its only previous owner).
So some context; I bought the car a year ago, as a commuter for when I go back to uni at the end of the summer, it's been in the garage waiting for me, and I'm just now financially stable enough to get her on the road. The car is perfect except for the headlight bins, which have gone cloudy after twenty years.
I've bought a set of replacement '04 lights from a breaker to replace the originals, and when I came to swap them earlier I discovered that one of the two connectors on the lights differ; the rounded 3 pin connector looks like it'll fit just fine, but there's a 4 pin rectangular socket on the new lights, whilst the originals have a couple of different plugs that go straight into the bulbs. (pictures attached of the new lights and current cabling) I assume that I'll need to get the plugs from the broken car that the lights came off to wire into the car to allow the old cabling to fit the new lights. My issue is that whilst I'm pretty handy with a soldering iron, I'm completely clueless when it comes to electrics. If anyone could help by telling me what wires should go where I'd be very grateful.
Tl:dr new headlights have a different connection to old and I need to figure out what wires go where.

New headlight socket

Old plugs in the car
Thanks in advance,
Owen

 

i believe the S40s came with both a two bulb and one bulb design which could account for the different connectors. The buckets also changed part numbers over the years so it seems like the two model years are not interchangeable. as far as the wiring goes, each bulb (ie high beam and low beam) needs a hot lead and they each need a ground. a quick volt meter test can tell you which is the high beam hot, low beam hot and which are the grounds. My expectation is with a three wire set up, you have two hot leads and one common ground.