Does The Curt Spectrum Brake Controller Dash Knob Light Up When Disconnected From The Trailer
Updated 11/17/2025 | Published 12/10/2024
Question:
Is there a test brake button like other trailer brake systems? Will the lights on the controller light up with no trailer hooked up?
asked by: Steve
Expert Reply:
Hi Steve,
The Curt Spectrum Brake Controller w/ Custom Harness # C36QV comes with a manual knob to mount to your dash that would allow you to manually activate the brakes, regardless of whether or not you have a trailer connected. Pressing the knob will bypass the requirements for it to activate and send a full 12 volts out to the 7-way to send out to the trailer's brakes.
The control knob will go to sleep when disconnected from the trailer so it's not constantly lit up, but if you press on it it would wake back up and show flashing blue lights. I've attached a diagram below showing the different light patterns and their meanings. If you have any other questions just let me know and I'd be happy to help.
(click to enlarge)
Product Page this Question was Asked From
Curt Spectrum Brake Controller w/ Custom Harness - Dash Mounted Knob - Up to 4 Axles - Proportional
- Trailer Brake Controller
- Proportional Controller
- Electric
- Plug-In
- Dash-Mounted Knob
- Behind-Dash
- Up to 4 Axles
- Indicator Lights
- Multiple Trailers
- CURT
more information >
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Jon G.
11/17/2025
Hey Steve, how did things go with the Curt Spectrum brake controller and its manual knob feature? Did the light patterns work as expected when you tested it without a trailer connected? Your update could make it easier for the next person setting up the same controller.