You may also want to check where the wires connect to the 6 pin on the backside. The connectors are not exactly water tight. I would grab some silicon and after inspecting them add a bit of silicon insurance to keep it from happening again. I carry a spare 6 pin as my last towed developed some corrosion on the wire harness side of it. Replaced it, but if I ever need to do anything with it, easier to just replace it than trying to clean the silicon off the backside of it.
2007 Fleetwood Excursion 40E
2007 Chev Classic CC LB D/A - Toad
2013 Jeep Sahara Unlimited - Backup Toad