Does anything plug in here: 92 500E radio?
 

http://fototime.com/41071F2D603B39A/standard.jpg

I had pulled the radio a few months ago and don't remember if any connector plugs in there and I don't find any that would, behind the console. After putting everything back together, the antenna doesn't work but I can't remember if it worked before I pulled the radio. This model doesn't have the antenna switch on the dash. Is that where the antenna connector should go?

mystery plug
 

I don't know what it is. If you have a voltmeter see if it has some voltage across the pins. Try this with radio off and radio on. If no voltage maybe it is for some input. If it's for the antenna motor you should be able to poke around and find it somewhere. It may be for some feature you do not have (extra speakers). Such a large white harness, so who know's what is in there. The antenna sounds about right, but a bit vague too since you're not sure if the antenna motor worked before you dismantled things.