Wiring An Electric Trailer Tongue Jack Into 7-Way Vehicle Trailer Connector

Question:

i have a 16 foot flat deck open car hauler which is running a 7 pin connector due to the electric brakes. i am replacing the hand crank A frame tongue jack with an electric tongue jack without a battery on the trailer. hopefully is there a method to toe into teh existing trailer 7 pin wiring so that when the trailer is plugged into the truck it powers the jack. Thanks in advance

asked by: Earl S

Expert Reply:

Electric tongue jacks like the Electric Jack w/ Footplate - A-Frame - 25-1/8" Lift - 3.5K - Black # EJ-3520-BBX are designed to use a 12v power so if you want constant power I recommend using a trailer battery for connection. If you only want power when connected to your vehicle 7-way, you can use the Pollak Black Plastic, 7-Pole, RV-Style Trailer Connector - Trailer End # PK12706 to connect to the 12v Pin.

expert reply by: Jason S

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Jody

4/27/2024

Can you do the same thing with a 4 pin trailer plug? Thank you in advance

Kevin C.

5/17/2024

@Jody A 4-pole trailer connector only has light functions and ground and wouldn't have the necessary 12v power for the trailer jack. If you can tell me the year/make/model of your vehicle I could find the parts needed to get you a 7-way.

Jody

6/21/2024

@KevinC Thanks Kevin, it's a 2021 chevy silverado trail boss 1500

Kevin C.

6/21/2024

@Jody If you have a 2021 Chevy Silverado 1500 you should already have a 7-way connector on the truck. For the trailer side you'll need a 7-way cable # A10-7W8 and a junction box # 3375601101. The junction box can be mounted on the trailer tongue and will be the connection point for the cable and the wiring already on your trailer. The trailer jack can be ran to the 12v auxiliary power post in the junction box so that it's powered by the tow vehicle when connected.

See All (4) Replies to Jody ∨

J.c.

1/7/2025

I think I have a similar situation. I have a 36 foot basic car hauler that our church uses for storage each week. I am replacing the manual jack with a power one and the unit comes with a black and red power cables just kind dangling off to the side. I don’t want to have an external battery, I want to plug up to the truck via 7 pin while using and that’s it. Is this the same 7 pin connector I would need to get and would I just attach the red to red and black to black on the 7 pin connector or something different?? Thanks!

Kate F.

1/7/2025

@Jc Who wants an extra battery if you don't need one? You can most definitely hook it up to the 7 way so you can power if from you trucks battery. You will want to double check the instruction manual to your jack, but the black should be your power and the red should be your ground (if you would like, let me know what jack you have and I will make sure). You will want to connect the power wire to the to the power portion on the # PK12706, and then you can ground the red wire straight to the frame of the trailer, or to the ground portion of the # PK12706 . I would also install a 30 amp. In-Line Circuit Breaker # 38630 close to the connector to save the jack from any power surges, you could also use a 30A in-line fuse, we only have them in 40A which is not recommended, but it would be like part # SWC9539. That is awfully nice of you to let your church use your car hauler for storage. May you have a Blessed 2025!