I have a 12 V Power Winch. The H3 has a 4 pin trailer hook up. How would one go about making a power source off the 4 pin, rather than to buy and install a battery on the tongue of the trailer?

 

the 4 pin might not be heavy enuf.

you might want to run a heavy wire from the batt for the winch depending on its current needs

 

definately run a heavier cable, keeps those little wires from smoking

 

Aha, I don't know the requirements yet. It pulls 2000 lbs. dead weight and 6000 rolling. All I want it for is to lift a gate on my trailer. The trailer is like a landscaper's trailer. Because I have an ankle locked with a pin and a total knee replacement, things cannot be lifted. I think you are right about hooking it up to the battery or buying a battery to put onto the trailer and just charge it when I get home. It only needs to function four times and then rest.
thank you for your input. Any other ideas will be well accepted.