most trailers have a tongue weight of 10 to 13 percent of Total Loaded trailer...


my 8,500 pound trailer has a tongue weight of 1,150 pounds. so a 3,500 pound tongue Jack will handle most 3 axle trailers.


google the 7 pin trailer connector and you will get the wiring and color codes...


and my 2012 had 7 pin and 4 pin from the factory.

 

If it's a factory installed 7 pin with the underhood relays you need the truck key on to get power at the plug.

 

That shouldn`t be a problem, as I will only need the jack when I hook the trailer on or off the truck.

I was just hoping I can use the 4 pin connector somehow to power up the jack.

 

NO Luck there... 4 wire,... tail light, left turn, right turn. Ground. NO POWER.


and not any one of them will handle 5 amps... much less a power Jack.


a single 12 gauge wire with a 20 amp fuse from truck battery to trailer jack .. and a single connector near jack to disconnect from truck.

 

I have the 7 pin connector too, so I can use that for the jack, I just did not want to mess with the 7 pin wires, to make sure I don`t screw up the brakes

And I wanted to use the 4 pin for internal LED lights ( enclosed trailer ) and I thought I can connect the jack to while I`m messing with the 4 pin, but if they don`t have enough amps, than I will only use the 4 pin for the LEDs.

 

I purchased my 28' TT with the electric tongue jack already on it. The PO just ran the hot lead from the tongue jack straight to the TT battery (fused of course) I like that way. I don't have to have it hooked to my truck to raise & lower it. Mine is a cheap one and water leaked into the head unit through the Bulls Eye level on the top (remove the Bulls Eye level to use the manual crank handle) I had to replace a micro switch. I now keep it covered with small bucket when it's stored to keep the rain out and keep a spare micro switch just in case.

 

That 10k tandem axle 20' enclosed trailer should have at least a small battery on it to power your brakes via the breakaway switch. It does have a breakaway switch doesn't it? That little battery should be getting fed by the 7 pin currently, so tapping jack power to it should be pretty simple. Sometimes those small batteries are tucked away, it may not be obvious but that trailer should have a complete breakaway system including battery.

 

Finally remembered to post a pic of my Husky jack installed. Totally happy.... it lifts the back of my Excursion no problem to allow me to grab the link I need with the snap up bracket.

 

I've got a Bulldog 3500# that's wired to my camper battery. It works....sometimes. Sometimes it works as it should and sometimes it barely creeps. I had to hand crank it today cause it drained the battery on the camper sitting in storage. But even the hand crank was 10x better then the factory hand crank Jack that was on it.

 

have the battery LOAD tested... after an overnight slow charge...

and have the 100 AMP LOAD test and ONLY the 100 amp load test... most auto parts stores do this for FREE. and get a print-out of the test.

all others are waste of time... if battery passes..

contact the company that made the Jack.. it maybe defective..