Thanks elliotgofast, some good suggestions there. The headlamp motor works okay for now, and you're right, the motor has a total of four wires going to it, which I haven't seen before. I do not know what happens when it reaches its end of travel - it does work okay, maybe this diode bridge has something to do with limiting the current spikes. Here's a photo of the motor:
I've got enough issues to resolve with this car, I'm not going to start "fixing" stuff that isn't necessarily broken at this time. I.E. the stuff that is working, I'm going to literally check it off the list / spreadsheet and move on.
I did clean up the diode bridge, but it didn't reveal anything additional, except "Made in Haiti", which is odd:
I ordered all the new wire for the harness, it should be here within a week. In the meantime, it's on to working on the brakes (which need everything too)...
-Wayne