Only large loads up front are the headlights and fan. Maybe the wire goes to a relay to feed one or the other.
I was thinking the same thing, that it was something removed in the past. Could it be an ahooga horn? I havent reinstalled that and I don’t see any wiring for it. But that seems kind of excessive for a horn…Picture one shows I’d guess a n 8 or 10 gauge wire to a 30-40 amp circuit breaker. That can support a pretty good load. Given there doesn’t seem to be any output wire near by it could be something that was removed from the truck in the distant past.
Picture two shows an ignition style resistor most often used to reduce 12 volts down to 6-9 into the coil when point ignition is used. That thought can extend into a few aftermarket and even factory electronic ignitions Chrysler did this on some models back in the 60’s and 70’s Ford and GM not so much.
Checked the specs for Mallory and it does call for the resistor. But thanks for the heads up!!I would have no idea, if there is no need for it I’d remove it.
I’d be more concerned with the ignition resistor and whether it’s really needed or not which takes you into identifying what’s inside the distributor by maker.
Started today 👍🏼Well start it up. If everything is working trace that wire back and cut/unhook it. If you cut it make sure to heatshrink it to avoid issues. I don't mess with that 70's resistor tech. Run a new wire etc if need be.