wiring connector near battery?-87 190d

[190jerry]

thanks to MTI for directions. my next question/problem?-I found a wire/connector that is not attached to anything-about 18 ga. with a round plastic connector-but nothing or any other connectors nearby. just in front of the battery. any ideas? a similar connector on the other side of engine(drivers side)-a round plastic connector attached to a square or oblong plastic connector.--still waiting for my "book" to arrive. BTW-fixed? the odometer, the pin that runs thru the numbered wheels had worked out so that the worm gear was not turning the gear on the pin, there was no "keeper" or evinence of one-I ran a piece of stainless s. wire across the end of the plastic gear and around the main body, and added a dab of grease-works good for now.