The jack is probably the highest amp draw of any 12 volt item on your rig. It is important that you have wire big enough to carry the load. The longer the wire run, the bigger the wire has to be. You would have to check to see if the existing wire from the battery to the distribution panel is big enough for the added load. If your trailer has slide outs, they are probably wired separately from the distribution panel for the same reason. The most efficent installation is to hook the positive lead directly to the battery using the jack manufacturer's supplied fuse. It is only one additional ring terminal on the positive terminal - doesn't seem like a big deal to me.
Bill & Kate - Stone Harbor, NJ
w/ Sunny (parti poodle) & Molson (goldendoodle)
2005 Ford/Quigley 4x4 E-350 Chateau Super Duty Van with 6.0L PSD ("Moby")
2012 Outback Super Light 277RL - 10th Anniversary Edition ("Salty Dog House II")
I ran my 3500 wire directly to battery as per instructions. Works great! Thought about the junction box but why? More work, same result.
Yeah, standard install instructions run positive to battery and grounding accomplished by by bolting to the frame. Since I remove my battery after every camping trip. I have the TT in storage and taking the battery home after every trip saves having to buy a new battery when some degenerate decides to walk off with it. So wiring to the junction block makes it easier to just drop the battery in and go. Junction box is not much farther than the battery box any way so no big deal to go there.
I agree. On mine, it looks like some degenerate already walked off with my battery (my batteries are in the enclosed underbelly -- AGMs). The wires out on the tongue are zip tied so they don't flop around and drag the ground. The positive wire is unhooked at the junction box. The batteries are hooked into the junction box with 6 guage wire and they are only about 6 feet long. There is not enough voltage drop to worry about it. The wire on my Atwood jack was exactly the correct length to reach the junction box.
Some day I expect to get pulled over by a LEO for not having a battery for the breakaway. All I have to do is unplug the umbilical cord and hit the switch on the Atwood to prove there are batteries there somewhere.
In the end assuming the proper gauge wire is used, it really does not matter. I imagine it is much simpler to state attach wire to battery when writing installation instructions.
Yes . . . it is much easier to instruct someone to attach it to something they see and know is there, rather than have them go hunt something down that may be in different places on different trailers and look different from one to the next too. My "junction box" was a piece of plastic placed in the floor of a trailer where water lines are brought up through the floor from the underbelly. Under it I found two breakers and a ground bar. One breaker was 50 amps. It had the wire from the battery on one side and the wires to the main panel and the breakaway switch on the other side. The other breaker is 30 amps. The wire from the "+" on the 7 pin goes to one side, and a short wire goes from the other side to the 50 amp breaker on the battery side. The "-" wire from the umbilical cord goes into the ground bar (same as the bar in the breaker box of your sticks and bricks). The plastic cover (i.e. the "box" described above) over this is no where near water tight.
All of the other wires from the umbilical cord are butt spliced to other wires under this cover . . . with the exception of the one for the backup lights -- which is just capped off . . . for now. I am going to put some LEDs on the back just so the idiots in my neighborhood can't claim they didn't realize the huge grey box was going backwards.
* This post was
edited 05/22/12 07:50am by ExRocketScientist *
I have the positive of my battery running to a disconnect using a 4 gauge battery cable. All my 12 volt systems and Barker 3500 jack run to the disconnect. When the disconnect is engaged the jack is inoperable with all other 12 volt systems.
I'm a newbie and thinking of purchasing a Barker electric jack, for my new trailer. I'm wondering if it's ready to hook up right out of the box? In other words, would I need to cut wire, splice in the fuse, attach the terminal end, etc? I live in an apartment and my tools are in storage and I'd have to do the work when I'm in a campground.