I'll be installing a power tongue jack. I do a fair amount of dry camping, which means I am frugal about my use of battery power. I selected a power tongue jack that uses less energy due to a ball-bearing design. I am thinking of wiring it to use tow vehicle battery power rather than directly wiring it to my trailer's battery. I would use the ground and lights connections on a flat-four connector, and I would plug this flat-four connector to the tow vehicle's flat-four port when I want to raise and lower the trailer. (I realize the tow vehicle's lights would have to be turned on to power this circuit.) I figure any time I need to raise or lower the trailer, the truck will be right there, because we'll be arriving at a site or leaving a site.What are the pro's and con's of this idea?Thanks in advance.-Speak

What happens if (and I say "if") your tow vehicle is not accessible (like, it gets wrecked, or in the shop for repair, or you are having mechanical problems) and then for some reason you need to move the camper. A different tow vehicle will not be equipped to operate the same as you are proposing. You can do it, and it will work, but you need a back-up plan if the tow vehicle is not accessible. Perhaps install an alternative plug off the trailer battery you can plug the power jack into for a "just in case" situation. I think then you'd have the best of both.Actually, if boondocking is your chosen style of camping, then you might be best to stick with a manual crank jack. Less dependency upon the battery that way.

Good idea, and simple enough to do. I'll do it.But any tow vehicle with a flat-four port will work. I won't be modifying the tow vehicle's wiring in any way.-Speak

SpeakEasy wrote:Good idea, and simple enough to do. I'll do it.But any tow vehicle with a flat-four port will work. I won't be modifying the tow vehicle's wiring in any way.-SpeakYou might want to add to your arsenal of "stuff" the 7 pin to 4 pin adapter plug for this very purpose. Not every vehicle is quipped with the 4 pin plug. Mine is not. I always keep a 7 to 4 adapter, especially since I also tow a 10 foot utility trailer that is wired for lights only.

I don't think it will work. Most vehicles taillights are wired with 18 gauge wire and fused for around 5 amps. You will probably end up blowing the fuse or burning up the taillight wiring in the vehicle.

Ah; good point. I didn't know that about the light gauge for taillights.So, I would be better off using the hot (battery-charging) circuit on the 7-round Bargman? Seems like overkill in terms of a plug, but if it would work, I could live with it.-Speak

Wiring for Power Tongue Jack | Good Sam Community

16 Replies

Jack_Diane_Free
Explorer
May 05, 2017
My original power jack quit working so I went to an industrial supply house (not RV parts store) and purchased a 3500 lb utility trailer power jack. It came with a 7 pin fit power cord and I just leave the truck running and plug it into the 7 pin receptacle on the truck. Works fine and does not consume trailer battery power. Yes there is an additional cord that just tucks under the propane cover when travelling and is no problem.
SpeakEasy
Explorer
May 05, 2017
Ah; good point. I didn't know that about the light gauge for taillights.

So, I would be better off using the hot (battery-charging) circuit on the 7-round Bargman? Seems like overkill in terms of a plug, but if it would work, I could live with it.

-Speak
1995brave
Nomad
May 05, 2017
I don't think it will work. Most vehicles taillights are wired with 18 gauge wire and fused for around 5 amps. You will probably end up blowing the fuse or burning up the taillight wiring in the vehicle.
DutchmenSport
Explorer
May 05, 2017
SpeakEasy wrote:
Good idea, and simple enough to do. I'll do it.

But any tow vehicle with a flat-four port will work. I won't be modifying the tow vehicle's wiring in any way.

-Speak

You might want to add to your arsenal of "stuff" the 7 pin to 4 pin adapter plug for this very purpose. Not every vehicle is quipped with the 4 pin plug. Mine is not. I always keep a 7 to 4 adapter, especially since I also tow a 10 foot utility trailer that is wired for lights only.
SpeakEasy
Explorer
May 05, 2017
Good idea, and simple enough to do. I'll do it.

But any tow vehicle with a flat-four port will work. I won't be modifying the tow vehicle's wiring in any way.

-Speak
DutchmenSport
Explorer
May 05, 2017
What happens if (and I say "if") your tow vehicle is not accessible (like, it gets wrecked, or in the shop for repair, or you are having mechanical problems) and then for some reason you need to move the camper. A different tow vehicle will not be equipped to operate the same as you are proposing.

You can do it, and it will work, but you need a back-up plan if the tow vehicle is not accessible. Perhaps install an alternative plug off the trailer battery you can plug the power jack into for a "just in case" situation.

I think then you'd have the best of both.

Actually, if boondocking is your chosen style of camping, then you might be best to stick with a manual crank jack. Less dependency upon the battery that way.

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Wiring for Power Tongue Jack

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