Ugh, that darn electricity is often tricky.
For the last few weeks, I have noticed my battery took longer to charge in the morning after start-up. Then one day I noticed my rear park lights, and dash lights were on, though the switch wasn't. Turning on the switch, turned on the front park lights, but still wouldn't turn off the rears.
I could not figure out how this could be happening, and only some of the time. On thursday morning, I went outside, and my darn rear lights were on again, and the battery was nearly dead.
Turns out, the spare fuse had partially slipped out from its holder, and was making contact from the brake curcuit, to the tail light circuit. Hard to believe that would be the only problem, on a 60 year old truck, with 60 year old wiring, with two fuses. I was ready for such a fight.
Boy am I happy.