[Lurayfarmer]

I don't think I was clear in my post. The truck has a "standard" 7-pin male plug with round pins. I'm converting to a 4-pin female plug with round pins. These adapters can be bought anywhere for $10. The issue is that ONE pin in the truck's plug is oversize and doesn't squeeze into a standard adapter. I'm assuming this is the power feeder for brakes but that's not important.