Originally Posted by former NXMX5
i’m fairly certain the brake switch is NOT hydraulic. its a contact closure that turn on the brake lights; purely electrical. the ABS/ESP/TC may use the brake switch for information (explaining the additional wires), but that too would be electrical.
try and check the switch to see if its sticking, or just not adjusted properly to be activated correctly.
What I meant by hydraulic, is that (unlike the switch on our clutch pedal) it plugs into the main ABS hydraulic unit vs being open/closed by the pedal arm itself.