Hi ratpH1nk,
You can get the entire hitch with wiring here and sell off the pieces to recover the vast majority of your spend????
2000-2006 BMW X5 E53 TRAILER TOWING TOW HITCH RECEIVER KIT w WIRING & MODULE OEM | eBay
Might be the best short term solution if you are in a jam to get your hitch set up operable??????
Mike