Troubleshooting A Curt Discovery NEXT Brake Controller That Is Manually Activating On Its Own
Updated 01/05/2026 | Published 09/16/2024 >
Products Featured in This Question
Question:
I recently bought a Curt Discovery braker controller from your site. when I installed it, I discovered that the controller is back feeding power to the breaks when they are not applied. When the trailer is hooked up it shows the M for manual mode when it is not being activated.
asked by: Kevin O
Expert Reply:
Hi Kevin,
If 'M' is showing up on your Curt Discovery NEXT Brake Controller # C38SV then that means the manual override is being activated. Is it giving you a number with that or just 'M'? I would check to see if your manual override switch might have something stuck in the spring/hinge preventing it from rebounding back out when not in use. If you slightly pull out on it does the M go away?
Product Page this Question was Asked From
etrailer Rubber Hitch Cover for 2" Trailer Hitches - Qty 1
- Hitch Covers
- Misc Covers
- Plain
- Rubber
- Fits 2 Inch Hitch
- Standard
- Square
- etrailer
more information >
Continue Researching
- Search Results: 500212
- Q&A: Does Curt Hitch for 2026 Toyota Corolla Cross Also Fit Hybrid Models
- Q&A: Recommended Hitch for a 2026 Toyota Corolla Cross and How to Install It
- Q&A: What's The Difference Between the etrailer and Demco Baseplate 2025 Jeep Wrangler
- Q&A: Will The etrailer Hitch e83ZR Fit A 2026 Subaru Forester Wilderness?
- Q&A: Can Locking Hitch Pin Replace Threaded Hitch Pin on Bike Rack for 2 Trailer Hitch
- Q&A: Recommended Flat Towing Parts for a 2026 Ford Maverick Lariat
- Q&A: Recommended Base Plate that Works With a 2024 Jeep Wrangler
- Article: Brake Controller 7- and 4-Way Installation Kit (ETBC7)
- Article: Which Hitches are Made in the USA
- Article: What RV AC Will Work With Your Setup? Avoid Costly Mistakes Before You Order
- Article: How to Clean Weld Nuts for the Installation of a Trailer Hitch | etrailer.com
- Article: How to Measure for Trailer Hitch Drop
- Article: 2 Steps for Finding the Right Weight Distribution Hitch Size
- Article: Wiring Trailer Lights with a 4-Way Plug (It's Easier Than You Think)


Robin H.
1/5/2026
Hey Kevin, did pulling out on the manual override switch clear the “M” on your Curt Discovery brake controller? Your update could make it easier for others who see the same issue.