Both my trailers have the junction box where the 7-way cable comes from the truck and is tied into the trailer safety lights and electric brakes. The only connection from this junction to the trailer system is one cable connecting to the + side of your trailer battery and of course also trailer frame ground. The safety lights and the electric brakes connections have nothing to do with your trailer 12VDC system.
I would open the lid of the junction box and see if the 7-way cable is wired into it COLOR FOR COLOR. It could be the replacement 7-way cable color code for the wires was not for the RV TRAILERS.
You can also go to ETRAILER.COM and look at their VIDEO on replacing this cable. Might give you some ideas. Also ETRAILER is the best place to purchase a replacement cable that comes in two different lengths. If I had cut my 7-way cable I would definitely replace it with a new molded cable in lieu of trying to replace the cut section by rewiring the leads using crimp on connectors etc. Just replace the whole cable with a new one would be my choice. ETRAILER also has drawings you can look at as well on how the safety lights and electric brakes are wired up.
I really don't know how any of this would be involved with the generator installation. None of these wiring cables has anything to do with 120VAC and are only powered by the truck rear connections that the 7-way cable plugs into.
The only possible connection might be the +12VDC lead where the generator installer may have used to get 12VDC to the generator instead of going directly to the battery terminals????
ADDED NOTE: When contacting KEYSTONE be sure you have your trailer VIN NUMBER handy. I know JAYCO is very good at providing any and all diagrams and schematic and build-outs just for the asking. They will send it to you via email in PDF FORMAT...
I was going to suggest it may need to go back to where you bought it from and let them handle then I noticed you are from Alaska = that is probably not doable there.
Roy Ken
My Posts are IMHO based on my experiences - Words in CAPS does not mean I am shouting
Roy - Carolyn
RETIRED DOAF/DON/DOD/CONTR RADIO TECH (42yrs)
K9PHT (Since 1957) 146.52M
2010 F150, 5.4,3:73 Gears,SCab
2008 Starcraft 14RT EU2000i GEN
2005 Flagstaff 8528RESS