electrical weirdness

Always look at the simple things first - in this case the fuses.

Yep, take out the suspect fuse and you will see it is corroded at the contact spots.

Several times I've just looked at a fuse and said OK. Then find out later that the fuse link has broken, etc. Auto electrical is a very mysterious, sneaky business. :-D

Once I had a 6-month old car blow a fuse when stepped on brake. It took me a week of no brake lights to find the cable was pinched under an external star washer and it took 6-months to finally cut through to the brake lite wire. I finally remembered a trick I'd seen a pro do once in a pinch: Replace the fuse with one covered with cigarette "tin foil" and let 'er smoke. Did the trick!

I don't necessarily recommend that!