Trailer Winch Wiring

   / Trailer Winch Wiring #1  

N80

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SC
Tractor
Kubota L4400 4wd w/LA 703 FEL
I've decided to get a winch for my 19' flatbed trailer. Getting the tractor on it is easy. Getting a low riding track car on it is a little more tricky. A winch would make it safer and capable of getting a non-running car back on the trailer too.

I've got an extra battery to run the winch off of but would like to wire it into my truck battery.

I'm hopeless when it comes to electrical matters.

eTrailer has a harness with 25' of red and black 3 ga. wire cable with quick connects. In their video they connect the cables directly to the battery terminals of the tow vehicle and run them directly to the positive and negative winch cables. This kit costs $119.00. (Almost as much as the winch I'm planning on buying).

I have several questions:

Do I really need 3 ga. wire for a 3400# ATV winch?
Shouldn't the negative wire be mounted to the frame of the tow vehicle and not directly to the battery?
The install video at eTrailer shows a circuit breaker/fuse coming off the positive battery terminal. It is not included with the kit. Do I need a fuse? If so, how do I know what size (amps?) fuse to get?

I'm thinking 8 ga. wire would be fine (total wild guess) and that I could buy the quick connectors and 50' of 8 ga. wire separately and spend a lot less than $119 but that is just a guess too.

Thanks for any help with this but remember I do not understand wiring. Any descriptions need to be at the 5th grade level or lower.;)
 
   / Trailer Winch Wiring #2  
All you need is a tongue storage box to install a HD battery to run the winch.
Mount winch on trailer and wire to the battery.
You also need to run a 10 ga. or larger wire from trailer battery minus terminal to trailer ground. this will be needed in order to complete the charging circuit when towing the trailer.
Your truck trailer plug wiring harness should have a 12V charge wire (usually a blue wire). That wire should be in the trailer side of the 7 pin harness and may be taped over or disconnected. Connect that wire to the trailer battery plus terminal so the battery charges while towing the trailer.
In the fuse box under the hood there should be a 30A fuse (or possibly 40A) that feeds that charge wire to the trailer plug. Replace that fuse with a 30A circuit breaker. That way the winch draws power from the battery on the trailer. If the charge wire gets overloaded the breaker will kick off then back on when it cools down instead of blowing a fuse.
 
   / Trailer Winch Wiring
  • Thread Starter
#3  
Thanks for the reply, but I'm mounting the winch with a box receiver so I can use it on the truck even when I don't have the trailer (and extra battery).
 
   / Trailer Winch Wiring #4  
OK, your first post said the winch was for the trailer. If you are going to use it in the truck receiver hitch then yes, you will need to run heavy gauge cable from the battery to the back of the truck. Even a small winch can draw close to or over 100A. I'd run #2 or 3 cable from the battery to the back and then use quick connect power plugs. Run 2 cables. Don't rely on the just the frame for a ground. Use connectors like these.Amazon.com: WINCH QUICK-CONNECT PLUG (175 AMP) - Set of Three (4X4 VEHICLES): Automotive
You can still do what I said in the other post when using the winch on the trailer.
 
   / Trailer Winch Wiring #5  
If you're looking for easy you could just use alligator connectors (like jumper cables have) and just pop your hood to connect them. A more clean look would be to run the cable under your truck. If you do one thing to remember is that you will want some sort of way to disconnect the power wire near the battery. If not and something shorts the positive wire to ground you will loose your truck from the fire that will ensue. It could be something as simple as a connector or a relay but you will want something.

As for wire size, every size wire has a certain amount of resistance. What will happen if you are slightly too small is the 12v at the battery will drop to the point where the voltage at the winch could do damage to it. The more current (amps) that flow through the power cable the more the resistance will become an issue. Also as the wire heats up it will also increase the resistance. Any winch you buy should have the maximum power required. With that you can figure out what the smallest size wire you can use. Most people don't go through that much work and just buy wire that's probably a little bigger than they need.
 
   / Trailer Winch Wiring
  • Thread Starter
#6  
Thanks guys. So if I get the right wire size and run them to the rear of the truck from each pole of the battery there is no need of a breaker or fuse somewhere in the line?

Crazyal, a disconnect is a good idea. Shouldn't be too hard to work that out.
 
   / Trailer Winch Wiring
  • Thread Starter
#8  
The kit at eTrailer was $119. I can put the same kit together via Amazon for about $60 using 4-awg wire and 350 amp quick connects (winch draws 240 amps). But then I saw a 25' 2-awg set of jumper cables for $30. Since my truck is almost 15 years old I might skip wiring it up and just use these jumper cables if I need them. Then, when I get a new truck I'll wire it up and I'll still have a good long set of jumper cables too.

Thanks for the help guys. At least I'll know how to wire the new truck properly whenever that time comes.
 
   / Trailer Winch Wiring #9  
A cheaper way is to use a set of jumper cables, 2ga ($30 amazon) cut the ends off, wire to the truck battery, run to the rear of the truck. Put a 400 amp quick connect and tie to the bumper or hitch. Then wire another quick connect to the trailer winch battery, or straight to the winch.Or make a short set of jumper cables, with a quick connect on on end and clamps on the other to jump either the trailer battery or winch, or a car that you can't get to from the front.
I use this setup to power a 12000b winch/receiver mounted, front and rear.
The small wires in a regular wiring harness, usually 10 ga at the most, cannot handle the winch 20' from the battery and usually cannot charge that second battery. And about every trailer winch that I have ever tried to use, the battery was dead when it was needed most.
 
   / Trailer Winch Wiring
  • Thread Starter
#10  
A cheaper way is to use a set of jumper cables, 2ga ($30 amazon) cut the ends off, wire to the truck battery, run to the rear of the truck. Put a 400 amp quick connect and tie to the bumper or hitch. Then wire another quick connect to the trailer winch battery,

That is a possibility.

And about every trailer winch that I have ever tried to use, the battery was dead when it was needed most.

Yep.
 
 
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