I had a 2100 apart not long ago, and I'm only going by memory here. I don't have a schematic. The 2100 has the warning lights panel on top that the LE does not have, and IIRC that accounts for the extra wire. Again, this is just from memory but two of the four leads attach to the same contact on the retractor spool casing. The male spade clip is made to accept to two females. The three contacts in the 2100 that I worked on were on one side of the spool casing. The contact in the middle of this group was the one that took two leads. Actually three, as two were paired in their spade clip. Wish I could take a picture and post it, but I don't want to take that thing apart again. If there's any doubt about where any of the wires go, don't connect them until you get a schematic or expert help.
The issue with mine was the cord retractor - spring broken. New cord and reel cost $30-something, so now I have a 2100 with a stationary cord. If my kids ask me what I want for a birthday gift, I'll tell them, a new cord and reel for my Electrolux 2100. They'll go, "Huh?"
The cord retractor is a weak link on these machines, I have since read on the internet. The spring was very cheap; I've seen heftier springs on Hoover Windtunnel and Kenmore canisters.