After pulling 30' of Misc. wire, you have to ask?

No, they work the same from about 1965 to present... they come on with the switch... I'd wager someone either tried a kill switch for running in the dark, or perhaps had gauges wired up previously..... attempted, anyway... The switch may have had a meltdown at some point, too, and they jury rigged something until it was repaired at a later date....
I had a 98.5 with the same problems.... Speaker wire was the primary conductor for gauges, mood lights, trick switches, and various other things I found under the dash... it was a bootbox full of snakes. I finally got most of it out, save a few trace wires that went to switches... It got real interesting when my hired hand hit a switch on accident, and about 5 minutes later, as I was following him, he pulled over and got out, along with a small cloud of smoke!! Apparently, the PO had no clue what a fuse was designed to do, and my rooting around under the dash with wire cutters had left some bare ends that were hot when the switch was on.... Melted a LOT of wires together. Luckily, most were in need of removal, anyway.... The PO was certainly not an electrical engineer..... That same truck I converted from an auto to a 5 spd for the PO..... When he wired up the reverse lights on a switch, he grounded them through the same circuit.... with the reverse lights on (which normally ground through the neutral start switch on an auto!!) the truck wouldn't start and run..... Anti-theft anyone? :-laf