Right-Hand Handlebar Switch Box | Honda CB350 / CB450 / CB500K / CB550
The right-hand switch box is one of the more commonly broken or worn-out electrical parts on a vintage Honda — and there are several different variants that look alike but are not interchangeable. This is the early-style box with the kill switch, the combination headlight control, and the electric starter button all on the right bar. It directly fits the CB450 K5–K7, CB500K, and CB550 (K and F), and can be adapted to several related models from the same era.
Why You Need This
Switch troubles usually come down to a broken wire or a worn contact inside the box, and once the kill switch, headlight control, or starter button stops working reliably, the fix is a fresh box rather than chasing the old one. The CB450 K5–K7 and the CB550 K and F models use their own special variant, designed around the front disc-brake setup where the master cylinder sits right next to the switch box. A single throttle cable runs out the bottom on the CB450; the CB550 uses a dual-cable setup.
What It Controls
- Kill switch on top — a three-position switch: the middle position is run, rocked up or down is off.
- Combination headlight control — off, low, and high beam all in one place.
- Electric starter button — presses to engage the starter solenoid.
Specifications
| Spec | Detail |
|---|
| Replaces OEM | 35300-310-673, 35300-319-670, 35300-455-670, 35317-235-000, 35318-259-000, 35300-341-671, 35315-235-000, 35300-292-670, 35300-323-671, 35300-300-674 |
| Directly Fits | CB450 K5–K7, CB500K, CB550K, CB550F |
| Adaptable To | CB350 / CL350, CL450, earlier CB450 (with the modifications noted below) |
| Style | Early-style: kill switch, combination headlight control, electric starter button |
| Sold As | Sold individually |
Fitment & Modifications
Drum-brake models (CB350 / CL350 and CL450) have the front brake lever perch built into the bottom half of the switch box. To run this box on a drum-brake bike, replace that built-in perch with our drum brake lever perch and front drum brake light switch.
Single-cable CB450. This box currently ships in the later dual-cable configuration used on the CB550K and CB550F. For a single-pull-cable CB450 we close the unused cable hole with a Delrin plug, so the box will look slightly different from the photo.
Left side. Many CB550 setups split the controls — hi-lo on the left bar, on-off on the right. Because this box combines both onto the right, our matching left-hand switch box has no hi-lo switch.
Wiring
The wiring on this replacement may differ slightly from your original factory unit — a wiring diagram is included in the product photos. Harness color connects to switch color as follows:
| Harness Wire | Switch Wire — Function |
|---|
| Yellow / Red | Yellow / Red — starter solenoid |
| Black | Long Black — 12V+ to the kill switch for the ignition coils |
| Black / White | Black / White — to the ignition coils |
| Black | Short Black — 12V+ for the lights |
| White | White — low beam |
| Blue | Blue — high beam |
| Brown / White | Brown / White — instrument and tail light |
The harness White/Yellow and Yellow wires have no matching leads on this switch. Join those two harness ends together in the headlight bucket — this is a common stator modification that keeps both halves of the stator charging full-time, and it is why an original nine-wire switch comes across as seven wires on the replacement.
Installation
Difficulty: Intermediate
Lace the wires through the bars. On factory handlebars the wires run inside the bar. Tie a piece of string to the wire ends and pull them through, and a spray of Windex on the wire housing helps them slide.
Aftermarket bars. Most aftermarket bars have no wire-exit holes. Either drill the holes to match, or notch the bottom of the switch box and run the wires externally along the bar — the video below shows the notch. The box also has an alignment pin that indexes a hole in the factory bar; it wiggles out with vise grips if your new bars are not drilled for it.
Give the buttons a ground. The horn and starter buttons ground through the handlebars and their mounts, so bare-metal contact matters. Paint or plating where the box meets the bar can block the ground, and rubber-mounted bars may need a jumper wire across the dampers.
Frequently Asked Questions
My old switch has nine wires and this one has seven. Do I need a modification?
No — that is expected. The two wires you do not see on the replacement are the stator-control leads (the harness White/Yellow and Yellow). Join those two harness ends together in the headlight bucket, as noted in the wiring section above, and everything else connects color to color.
Will this fit my CB350 Four?
No. This box fits the CB350 and CL350 twins, not the CB350F Four. Double-check which model you have before ordering.
I have a drum-brake bike. Can I still use this box?
Yes, with the perch conversion. Drum-brake CB350 / CL350 and CL450 models have the brake perch built into the box, so you will add our drum brake lever perch and front drum brake light switch to make it work. Both are linked above.
I have a late CB550K. Is this the right box?
Later CB550K models (1977–78) moved to an always-on headlight circuit with no on-off control, and use a different box. If that is your bike, see our always-on right-hand switch box instead.
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Last updated: July 2026
