Connectors on wiring harnesses are a perpetual weak point. GMWillys can speak to that on things other that old Jeeps.
I put a replacement wiring harness on the '48 and all in all it was great - but there was one oh-by-the-way.
The horn might or might not blow when I wanted it to hoot. I lived with it for a year or so, then one day when I had nothing else to do (!) I went bug hunting. I finally ended up at the middle of the steering wheel under the horn button. It turned out that the connector on the horn wire had been crimped on insulation, not the copper conductor (well, just barely on some copper).