65 Dart Wiper Switch Breaker

There is no way I would NOT try to "go around" that. I've never had one of those apart. Is both sides of the breaker brought out to a terminal? Looks like the B -- B terminals are. If so that would be VERY easy, you just feed 12V from a fuse / breaker into the "other end of the internal breaker.

If not some work with a dremel should get you a small area to install a jumper across the original breaker.

This is the closest I can come to matching up what you have.........