Gah...
Still working on that bass. Electronics seem to be borked worse than I thought.
I replaced the input, but that didn't help with cleaning up the signal. It's still intermittently fuzzy on pretty much every setting. The problem is, I can't tell if it's the parts bin 3-way switch, the pots, or the pickups. The pots were frozen solid when I got the thing, so they very well could be trash. That said, I am getting the most noise when futzing with the switch; there was a reason why I had replaced it on my Explorer, as it felt a little on the loose side. I may have to just bite the bullet and replace all the pots and the switch. It's still worth the investment; the thing looks and feels great.
For reference, here's the wiring cavity before I replaced the switch.
Seems like your standard Jazz Bass style harness, but there's a switch and some filter caps and the pots are 500k instead of 250k. I was thinking of just getting a pre-made harness like this:
This is a "guitar" harness, but other than the filter caps, it seems to be identical. Any reason why I couldn't just stab this in there?