What to Check
Check whether the horn sync line and the high-beam sync line are properly connected with solid contact, and confirm that the two lines have not been connected in reverse.
When either sync line is loose or reversed, the controller can misread the signal as a continuous high-beam trigger, forcing the spotlights to stay at full brightness and overriding your controller input.
What to Do
Turn off the ignition and disconnect power.
Locate the horn sync line and the high-beam sync line at your controller wiring.
Confirm each line is securely connected to the correct circuit — the horn sync line to your horn signal, the high-beam sync line to your high-beam signal.
Verify the two lines have not been swapped with each other.
Reseat any loose connectors firmly until locked in place.
Restore power and test again.