Electric tongue jack for my `72 Safari

[Tom Bray]

A friend of mine gave me an electric tongue jack after he decided not to use it on his Airstream, he bought a new one instead. I would like to use it.

I checked it out and it appears to be fine, although I haven't mounted it on my camper. It is rated for 3500 lbs. It has a 10 gauge wire and a 30A fuse. Testing it, the motor draws a lot of current at startup, then it settles down to something reasonable, 5A or so while running, I'd expect it to use more under load jacking up the camper. I looked in my manual and the directions recommended hooking an electric jack to the brake safety switch which is a 12 gauge wire. My reprinted manual doesn't show the wiring for the safety break away switch, so at the moment I have no idea where it connects to 12V.

I am thinking it might be better to run a new wire, either from the fuse block at the rear or connect it to the big charging wire at the front where it ties into the vehicle wiring. Neither appear to be easy to do unless I run it on the outside next to the gas line.

I don't recall seeing the brake wires when I had the front belly pan off.

I keep questioning why it takes so much power to move 600lbs of tongue weight.

Any recommendations
Tom

[Lumatic]

The 3500# jack would be quite normal for this application. Most are wired into the break away switch.

I handy accessory is a hand crank for the jack in case it fails for some reason.

[Phoenix]

I crimped a lug onto the power lead and connected it directly to an unused "positive" marine terminal (thumb nut) on one of the batteries in the battery box. This keeps the electric tongue jack circuit separate from the breakaway switch (a safety item).

[Tom Bray]

I connected the electric jack to the power side of the breakaway switch and it seems to be working. I tried jacking up the trailer several times, stopped in the middle and started it up again, all with no adverse affect. I may still run a separate line but I'll do that after I figure out where all the wiring goes.

If I ever blow the a fuse related to the way I have I wired up now I'll know which circuit it is and then decide how best to fix it. My testing should have blown a fuse if the circuit is under powered. If I blow a fuse, I have a whole kit of replacements in the camper.

It wouldn't surprise me that the breakaway switch is connected to the vehicle charging circuit, that would feed it from both the camper battery and, assuming the vehicle cable is still attached, the vehicle battery. I was hoping someone who has checked this out would comment. To disable the vehicle charge circuit requires disconnecting wires since that circuit is protected by auto resetting breakers at both ends of the wire, not a standard fuse.

Tom