Choose the left or right replacement switch assembly for your 1980 CB900C Custom before comparing its plugs. Both black assemblies use wiring outside the handlebar, an important detail if the motorcycle has altered bars, rerouted wiring or earlier replacement controls.
The featured left and right switch assemblies use external handlebar wiring. Compare control functions, connectors and the installed loom before replacing a housing, particularly on a motorcycle with modified bars or wiring.
The left assembly operates turn signals, horn and lighting. The right assembly is the brake-side control. Match each replacement to the installed controls and use its wiring instructions; connector appearance or wire colour alone does not prove a correct circuit match.
Protect the wiring at the bars
Keep the loom clear of sharp edges and pinch points, allow steering movement without pulling connectors, and secure the external wiring appropriately. After fitting, verify all affected controls and check that the throttle and cables move freely before riding.
Practical questions
Does one failed horn or signal function mean the whole left switch needs replacing?
Check the affected lamp or horn circuit, connections and switch continuity first. A supply, ground or downstream component fault can look like a defective switch assembly.
Can matching wire colours be used as the only installation guide?
No. Compare terminal positions and circuit functions with the exact-year wiring diagram and replacement instructions. Previous repairs or aftermarket parts may use different colours or arrangements.
What changes if the bike has taller or different handlebars?
Check that the leads reach without tension and that the housings and cables fit the bars. The listed external-wiring arrangement does not establish suitable lead length for every handlebar conversion.
Not sure which part you need?
Send your model and year, plus photos of your existing part and any changes to the original setup.