Trailer wiring help

I use a snowplow connector. But I ran a no 6 back the frame and tied it to the truck battery. I do not have a battery on my trailer for the winch. And I also have another trailer that is a dump. I use the same connector to run it when am hooked to it. But 67dart273 makes me question that hookup because I run it off of the truck battery. And he sounds far more knowledgeable than I. And when I am using my winch or my dump I leave my truck running. Here is an ebay link to the connectors...I think.

[ame="http://www.ebay.com/itm/QUICK-CONNECTOR-KIT-175A-RED-WINCHES-SNOW-PLOW-TOWING-4X4-QUAD-SALT-TRUCK-/130814064036?pt=LH_DefaultDomain_0&hash=item1e752035a4"]Quick Connector Kit 175A Red Winches Snow Plow Towing 4x4 Quad Salt Truck | eBay[/ame]