Recommended Hitch and Wiring for a 2021 RAM Promaster 2500
Updated 09/29/2025 | Published 09/05/2025 >
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Question:
We have a Dodge Promaster 2500 Extended 159 wheelbase and high roof. It has a 3.6 L V6 24V VVT Engine with a 6-speed Auto 62TE Trans. We want to add a tow hitch with a wiring harness but too many choices and not sure what to get. Vin if it helps is 3C6-LRVDG7ME-548315. We intend to pull a 6x12 trailer full of contstruction tools, etc. I dont ever see the gross weight wed tow over 5,000lbs so please recommend a complete set up. Thanks,
asked by: Dave M
Expert Reply:
Thanks for the information Dave! To add a hitch to your 2021 RAM Promaster 2500, I recommend the Curt item # C13295. This is custom fit, class III hitch with a 2" receiver, that has a 5,000 lbs towing capacity and a 500 lbs maximum tongue weight.
Since your Promaster does not have the factory tow package you'll need to install two separate wiring harnesses to be able to pull a trailer with brakes. The first one is the Curt T-Connector Vehicle Wiring Harness item # C58DR. This custom-fit T-connector plugs into your Ram's wiring harness, which is located in your rear cargo area, behind the rear access panels. It will provide you with a 4-way connector.
The second harness you will need is the Universal Installation Kit for Trailer Brake Controller item # ETBC7. The kit includes a pre-wired 7- and 4-way trailer connector that mounts easily at the rear of your Promaster with an included bracket. This kit is designed for use on a vehicle with an existing 4-way flat trailer connector and plugs directly into it.
You will then connect the blue wire to the blue wire on the brake controller, connect the black wire to the positive post on your Ram's battery, the white wire to a suitable ground, and the yellow wire to the accessory circuit. This will provide you with the ability to control your trailer's brakes and also provide you with a 12v power wire for you cargo trailer's battery.
Do you have a brake controller? If not, I recommend the Redarc Tow-Pro Liberty Brake Controller w/ Universal Wiring Harness item # RED52VR. This is a proportional brake controller that automatically adjusts your trailer's braking based on the deceleration of your Promaster. The Tow-Pro has a unique installation method where the main unit is concealed behind your dash and the only part visible is the control knob.
Product Page this Question was Asked From
Curt Trailer Hitch Receiver - Custom Fit - Class III - 2"
- Trailer Hitch
- For Towing
- Class III
- 500 lbs TW
- 5000 lbs GTW
- 2 Inch Hitch
- Concealed Cross Tube
- CURT
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Jerred H.
9/29/2025
Hey Dave, did you have a chance to set up the hitch and wiring harness on your Promaster? I'm curious to know how it worked out for towing your trailer, as it could help others with similar setups.