This is for a 1990 Park Ave. Instructions say there is a single black wire along the right side panel in the back by the power antenna. Mine doesn't have that. I have a dead remote due to dead batteries. I have a feeling that once I get new batteries that it'* going to have to be re-synced.
Does anyone have any ideas on how to do this?

I don't think there will be an issue with the remote after a battery change, but I may be wrong. If reprogramming it is anything like the Bonneville of that time, there will be a pair of wires coming to an empty plug clipped to the side of the glovebox. Glovebox will need to be popped out, then it would be to the left of it, clipped inside of there. Jumper the wires, the locks will cycle, hit a button on one of the remotes you wish to use, locks should cycle again. Same thing will all other remotes you have.

Ok, I DID see those yesterday. But I didnt dare do anything with them. The car is almost new.. dont want to screw anything up.