Troubleshooting Flat Tow Wiring and RoadMaster Invisibrake System on a 2025 Jeep Wrangler Sahara
Updated 06/08/2026 | Published 05/25/2026
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Question:
Curt Custom Tail Light Wiring Kit for Towed Vehicles Part Number: C96JR Installed this on my 2025 Jeep Wrangler Sahara. I am now installing a RoadMaster invisibrake. I thought this harness had diodes in to prevent electrical back flow. When my jet is not connected to my RV and I press the brake pedal on my Jeep, it appears power is getting passed back to the brown wire on the toad wire which in turn activates the Invisibrake to brake. It looks like I need to install the RoadMaster 4 Diode kit. Roadmaster Hy-Power Diodes Qty 4 RM-794 Thanks
asked by: Chris E
Expert Reply:
Thanks for reaching out Chris, happy to help!
The Curt Custom Tail Light Wiring Kit # C96JR does have diode protection for the tow wiring, so we would not recommend adding the Roadmaster 4-Diode Kit # RM-794.
From what you're describing, it sounds like the InvisiBrake is seeing a brake light signal from the Jeep and interpreting it as a command to activate.
The Roadmaster Brake Light Switch Kit # RM-751490 would be the better option to look at. This kit adds a dedicated brake pedal switch that provides a separate signal for the Invisibrake, helping it distinguish between normal vehicle brake lights and braking while towing. On newer Jeep Wranglers, this is a common solution when integrating a supplemental braking system such as the InvisiBrake.
Would this be the first flat tow with the Jeep Wrangler?
Alex
6/4/2026
I installed it on my 2026 Jeep Sahara and it seems to work fine when I tow my Jeep. My problem is with the third pigtail that I assumed would allow me to hook up a trailer wire when I tow something with my Jeep. According to them it does nothing. I know it has no ground wire. I have no idea why it is on there. If anyone knows what it is for and how to utilize it, please tell me.
James D.
6/5/2026
James D.
6/5/2026
Product Page this Question was Asked From
Curt Custom Tail Light Wiring Kit for Towed Vehicles
- Flat Tow Wiring Harness
- Plugs into Vehicle Wiring
- Wiring Harness
- Custom Fit
- 4 Flat
- CURT
more information >
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Chris E.
5/30/2026
Well the Curt wiring was allowing signal, from the Jeep OEM circuit, back into the flat tow wiring. The way the Inviisbrake detects braking is from the RV, through the umbilical cord, into the flat tow wiring. I butchered the Curt wiring and removed the quick connects, in the Jeep tail lights, and installed the Invisbrake Diodes at the Jeeps rear lights. Everything works fine now and the Invisibrake works fine. I did rewire the 4 pin trailer pigtail as it now connects downstream of the diodes. From your last question, I previously had a Patriot 3 (BLU37TR) system, purchased from you in March 2025, which has quit working. I will be sending it back to BlueOx for repair, I have had correspondence with them and they think it's the capacitor, but with my travel plans I dp not have time to wait for the repair, hence me installing the Invisibrake.