Replacement 945203-00 Harness for a Roadmaster InvisiBrake Flat Tow Brake System RM-8700
Updated 10/22/2025 | Published 09/16/2025
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Question:
I just bought a 2011 Smart Fortwo car with a tow package with invisibrake. Everything appears to be installed, including the break away switch up front, however there is no wiring to the module connector for 12v power and the break away. The four wire lighting connector is present. Why would that have been omitted? Confused? thank you,
asked by: Allen B
Expert Reply:
Either someone messed up installing the Roadmaster InvisiBrake Flat Tow Brake System item # RM-8700 or it was intentionally removed. You'll want to contact whomever you got it from, if that's an option, to see if you can find that 945203-00 harness. If you're not able to retrieve it that way you'll want to reach out to Roadmaster directly because we do not offer that as a replacement part and I do not see it on their website.
The only solution I have for you is to purchase the Second Vehicle Kit for Roadmaster InvisiBrake Flat Tow Brake System item # RM-98700, which includes that harness.
Where did you get your Smart Fortwo from and do you need any other parts to flat tow it?
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Product Page this Question was Asked From
Roadmaster InvisiBrake Flat Tow Brake System - Preset
- Flat Tow Brake System
- Brake Systems
- Pre-Set System
- One-Time Setup
- Vehicle Battery
- Fixed System
- Power Assist Brake Compatible
- Air Brakes
- Hydraulic Brakes
- Indicator Lights
- Roadmaster
more information >
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Jerred H.
10/22/2025
Hey, were you able to track down that missing harness for your Smart Fortwo’s InvisiBrake system? Knowing how you resolved it could really help others who run into the same wiring issue.