Ignition switch electrical gremlins = SOLVED

[deuchant420]

HI all, I have had many problems with my E53 since owning it. The electrics have been the most frustrating issues as they are very difficult to diagnose. The latest issue has been the ignition switch. The X5 has had an intermittent starting issue where it would sometimes just do nothing when the key was turned to the start position. I replaced the battery, the starter, the fuel pump relay(separate issue) and went through every fuse, relay and the main components in the E box. Every connection was cleaned and checked. I even removed the ignition switch, took it apart and cleaned and rebuilt it. Nothing seemed to help. It would still just not start at random. However, the other day I had more strange issues pop up. First, my seatbelt warning started going off. Then the airbag light went on and off. Finally my rear wiper stopped working, then the front wipers. This is what really got my attention. I went through every component again. Finally I remembered reading about the visor test. Even though the ignition switch looked perfectly fine when I examined it, I decided to do the visor test. Sure enough, when I opened the vanity mirror the light did NOT come on. Instead the airbag light went off and my 3rd brake light came on! (other issues with this were: heated seats did not work, all steering wheel controls not functioning, wipers only having power in key position 1, false trans failsafe warning on dash, brake light warning on dash, radio weirdness)
I picked up a new switch at the dealer $112 as I didn't want to wait for an on line order. The tech at the dealer gave me a GOOD TIP: Look for blackening on the switch terminals and harness plug. These are signs of tarnishing from high voltage and can cause voltage drop and no connection issues
I replaced the switch and now everything functions as normal. I did clean all of the receptacles in the harness plug with emery cloth, MAF cleaner and a paper towel just to be safe before replacing the switch. This did not help, the switch was no good.
So, the motto here is, if you're having any of these symptoms, look for tarnish and replace the switch even if it looks fine.
I hope this helps someone with their electric gremlins. Only time will tell if this solved the no start issue, but I have to believe that it did since all of the other symptoms were corrected.
Cheers
2005 X5 4.4