Will Curt Tester Work on 2018 Volkswagen Atlas With Trailer Detection

Updated 02/05/2026 | Published 01/31/2026

Products Featured in This Question

Redarc Tow-Pro Elite Brake Controller - Dash Knob - Off-Road Mode - Up to 3 Axles - Proportional

(1691)

$290.00

Redarc Tow-Pro Wiring Adapter for Curt Brake Controller Harness

(7)

$27.00

Curt Custom Wiring Adapter for Trailer Brake Controllers - Dual Plug In

(15)

$26.42

Curt 7-Way to RV Socket LED Circuit Tester - Vehicle End

(183)

$20.10

Question:

I have a 2018 VW Atlas with factory installed towing package. I am installing a Redarc Tow-Pro Elite brake controller as I am purchasing a new camper with electric brakes. I am picking up the camper from over 800 miles away from home, so I want to be sure before I head out that everything is working as far as lights and brake control to the camper is concerned. I cant find positive confirmation that this Curt 7-way tester or any of the other similar products will actually work on my Atlas that has trailer detection built in. Will the Curt C73NR adequately simulate an actual trailer and function to test my wiring?

asked by: Steve W

Expert Reply:

Hey Steve! Yes, the Curt 7-Way Tester # C73NR will work with your 2018 VW Atlas with the factory tow package. The tester plugs into your 7-way and confirms that the wiring is functioning, including lights, 12V power, and brake controller output via manual override. It will allow you to verify your Atlas is sending the proper signals.

While the # C73NR does not apply a load to the brake circuit, and cannot fully simulate a trailer with electric brakes, you can still power and calibrate the Redarc Tow-Pro Elite # RED44FR without a trailer connected. The tester can be used to confirm brake output is being sent, but final brake performance should be verified with the trailer connected or with a battery powered trailer end tester.

For a plug and play installation you will also need the # C51522 and the Redarc Tow-Pro Wiring Adapter for Curt Brake Controller Harness # 331-TPH-019.

What kind of camper are you picking up?

expert reply by: Robin H

Curt 7-Way Tester
(click to enlarge)

Steve W.

2/4/2026

Thanks for the info, it's very helpful! I'm picking up a Prolite Classic camper. Super excited! FYI, I've already been down the path with the C51522 Curt branded adapter harness for the Atlas and the 331-TPH-019 harness to connect to that to the brake controller. While etrailer website claims plug-and-play fit, the C51522 adaptor harness does NOT fit my 2018 VW Atlas (pins are much too wide and overall connector end is much too big relative to VW plug). I've returned those parts to etrailer and purchased a pigtail elsewhere that fits my Atlas and I wired the bare ends of it directly to the bare ends of the Redarc connector harness included with the Redac Tow-Pro Elite brake controller. I've not installed it all yet, but I see no reason it won't work (and that's what the Curt 7-way tester is for :-). Steve

Robin H.

2/5/2026

@SteveW I wonder what is going on with that wiring harness. I don't think we have had one in to install so we have to take the word of Curt on something like that. I'll check and see if they have heard anything about the plug being different. Either way, it sounds like you got it taken care of. Enjoy your new camper and be safe out there!