I have a 1997 Mystique (manufactured in 1996) that will, on occasion, simply die. No electric of any kind, anywhere.
I have discovered that if I fool around with the connector in the photo, it usually comes back to life. It could be a coincidence, as it is right next to the battery, but it does seem to work.
Problem? I have no idea what this is, nor does any amount of searching on line seem to reveal it, nor do any of my friends. It _really_ disappears into the engine compartment, and I have not been able to trace it. The images show it in place, and the the top and bottom of the connector, apart.
So first, hopefully someone does know what it is, and secondly, I would be glad to entertain any other suggestions as to the issue.
BTW - yes, I have removed, cleaned, and tightened the battery terminals, and the battery is very strong.