How to Upgrade 4-Way Wiring on Vehicle to Match 7-Way Wiring on Trailer
Updated 08/18/2025 | Published 07/25/2025
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Question:
Hello, I have a 4 way connector installed on my car for towing, but the camper I pull has a 7 way connector. The 4 way flat doesn’t charge the battery as we drive, and I believe a 7 way would. Could you send me some options that I could purchase that include the battery charging. Is there a way to adapt the 4 way wiring I currently have, or would it require a whole new system? The 4 way is connected to the battery of the car. Appreciate the help. Thanks
asked by: Nick W
Expert Reply:
Hey Nick, thanks for reaching out!
Your Curt Powered Tail Light Converter # C59236 has that power wire just to power the lights on your trailer so they don't draw on the circuits of your vehicle.
To upgrade your wiring you'll need the Universal Upgrade Kit # ETBC7. This plugs into your current 4-Way and then you run an additional wire up to your battery to power the 12V power pin on the 7-Way.
One thing to note is that you're going to get a trickle charge from this setup. It will keep your battery level from dropping, but it won't charge a depleted battery. In order to actually charge the battery you're going to need a charger that pulls power from a wall outlet or you'll need to install something like the Redarc BCDC # RED96FR to actively charge while driving.
Were you thinking about charging the battery, or more like keeping it topped off?
Product Page this Question was Asked From
Curt Powered Tail Light Converter with 4-Pole Flat Trailer Connector
- Custom Fit Vehicle Wiring
- Trailer Hitch Wiring
- Vehicle End Connector
- Powered Converter
- Universal Fit
- 4 Flat
- Plug and Lead
- Splice-In
- CURT
more information >
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on Custom Fit Vehicle Wiring
Jon G.
8/15/2025
Hey Nick, Did you decide to go with the Universal Upgrade Kit to keep your battery topped off, or are you considering the Redarc charger for active charging while driving? I'm curious to know how it worked out for you, as it could really help others in a similar situation!