Old, cracked, ATF-soaked connectors with tired oval contacts (remember your question about that?) have been known to do funny things. The center pin is supposed to get GROUNDED when working properly, and do it in Park and Neutral (see the synchronicity there?).

It's not a percentage bet, but it is an easy test to pull out the ohm meter. I could have gotten in my car and driven up there and tested it myself in the time I spent typing out that you should take out your ohm meter.

Okay, maybe that was a slight exaggeration...