Winch wiring question for trailer

[Rockn H]

I try to stay away from battery isolators because for me they always seem to go bad and drain both batteries with me finding out when I try to crank the truck. ;)  On my big truck we use a ford starter silenoid to run the extra parking lights because they can handle a lot more amps than most of the relays you find and long term use is deffinately not a problem.  For aux winch batteries, we use a starter silenoid activated off the ignition switch and 6 ga wire between batteries.  This way if you run the battery down winching, with the truck off, you still have enough juice in the main batt to crank the truck.  If your winching with the truck running, the starter silenoid can handle the amps and so will the 6ga wire.  With the silenoid activated off the ignition I don't have to try and remember to turn it on or off. ;)

[rebocardo]

RocknH, excellent points and how to.

In my own Ford truck, I do have two starter relays under my hood. One for the starter itself and the second on the other side of the engine running my rear lamps and relays for the trailer lamps. The Ford starter relays do make excellent high current relays. Certainly cheaper then the $100 100 amp ones that always fail used on power tailgates and such.

Plus, if my starter relay does fail, all I have to do is grab my "spare" on the other side of the engine and drive without rear lamps. For $10 it sure is handy.