Was doing a pre-ride inspection of all my lights today and found the front brake switch was not working to actuate the rear brake light. Removing the 2 wires from the switch revealed some corrosion. Removed the switch from the front brake handle assembly and cleaned the wire terminals, the switch terminals, and sprayed some contact cleaner into the switch with the button depressed. Then I lubricated the switch, terminals, and leads with some dielectric grease. After reassembling, got the desired result. Handlebar brake lever now actuates rear brake light too.
