Rear Brake Light Switch | Vintage Honda Motorcycles
Rear brake light not coming on when you step on the pedal? The switch is either broken, corroded, or out of adjustment. This OEM-style replacement fits virtually every vintage Honda from the CT90 through the CB750.
Why You Need This
The rear brake light switch is a spring-loaded contact switch mounted near the rear brake pedal. When you press the pedal, the spring pulls the switch plunger and closes the circuit — lighting up the tail light. After decades, the spring stretches, the contacts corrode, and the switch stops working. If the car behind you doesn't know you're braking, that's a safety problem and a failed inspection.
Our replacement is a direct-fit OEM-style switch. Available by itself or with a replacement spring as an optional add-on at checkout.
Specifications
| Spec | Detail |
|---|
| Replaces OEM Part Numbers | 35350-KJ9-405, 35350-336-000, 35350-098-005, 35350-028-000, 35350-051-000, 35350-098-003, 35350-102-405, 35350-046-023, 35350-102-770, 35350-086-721, 35350-GB2-505 |
| Fits Models | CT90 K5–K9 (1974–1979), CB100/CL100/SL100, CB125/CL125/SL125, CB175 K3–K7 (1969–1973), CL175 K3–K7, SL175 K0–K1, CB200 K0/T, CL200, CB350 K0–K5 (1968–1973), CL350 K0–K5, SL350 K0–K2, CB350F, CB360G/T, CL360, CJ360T, CB400F, CB450 K1–K7 (1968–1974), CL450 K0–K6, CB500T, CB500 K0–K2, CB550 K0–K1/K/F, CB750 K0–K8/F0–F3/A |
| Replacement Spring Length | 3.375" / 85 mm (fits most models) |
| Sold As | Individually — spring available as optional add-on |
Does NOT fit: CT90 K0 through K4 (earlier models use a different switch) or CB450 K0 (Black Bomber — different rear brake design).
Spring length note: Honda used many different spring lengths across models and years. Our replacement spring (3.375" / 85mm) fits the majority of bikes. Models marked with * in the fitment chart — SL350 K1-K2, CB500K, CB550K/F — use a longer spring that will NOT work with our replacement. You must reuse the original spring on those models.
Installation
Difficulty: Beginner
- Disconnect the old switch — Unplug the two-wire connector from the old switch.
- Unhook the spring — Remove the spring from the switch and the brake pedal anchor point.
- Remove the old switch — Unscrew or unclip from the frame mount.
- Install the new switch — Mount in the same position. Attach the spring between the switch plunger and the brake pedal anchor.
- Adjust — The brake light should turn on just as the rear brake pedal begins to depress. If the light stays on constantly, the switch is over-tightened or the spring is too short — back off the adjustment until the light goes off at rest.
Common mistake: Over-tightening the switch so the spring constantly pulls the plunger. This causes the brake light to stay on all the time. The fix is simple — loosen the adjustment until the light turns off when the pedal is at rest.
Frequently Asked Questions
Will this fit my CL175?
Yes — it fits all CL175 K3 through K7 models (1969–1973). Same switch as the CB175 and CB350.
My brake light stays on all the time — is the switch bad?
Probably not. This usually means the switch is over-tightened or the spring is too short. Loosen the adjustment until the light turns off when the pedal is at rest, then fine-tune so it activates just as you start pressing the pedal.
Do I need the spring?
Check your original spring — if it's stretched, rusty, or missing, add the replacement spring at checkout. If your original spring is in good shape, reuse it. Models marked with * in the fitment chart (SL350 K1-K2, CB500K, CB550) MUST reuse the original longer spring.
Does this fit the front brake too?
No — the front brake uses a different switch. Drum brake models use a lever-perch mounted switch. Disc brake models use a hydraulic switch on the master cylinder.
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Last updated: March 2026
