6-Pin Plastic Wiring Harness Connector | Vintage Honda CT90 Through CB750
A replacement 6-terminal plastic connector for vintage Honda wiring harnesses, with male and female housings and brass spade terminals. Made in Japan. On the CB500K, CB550K, and CB550F it's the connector the rectifier plugs into, and it's the fix for converting an early CB500K0's round-pin rectifier plug.
Why You Need This
The plastic components of your vintage Honda are prone to deterioration over time, and the multi-pin plastic connectors in the electrical system are no exception. They go brittle, crack, lose their locking clips, or fill with corrosion until the inner terminals look like a snow globe. We had a pristine CB360 in this exact situation, causing all kinds of electrical havoc. These connections can cause some very weird gremlins, which is why we often replace every white plastic harness connector on our own bikes.
The factory terminals were only crimped into their connectors, not soldered. Solder the new ones, add a dab of dielectric grease, and heat-shrink each wire up to the connector, and the connection becomes quite bulletproof.
Specifications
| Spec | Detail |
|---|
| Type | 6-terminal plastic wiring harness connector, male and female housings |
| Terminals | Brass spade terminals |
| Made In | Japan |
| Recommended Wire Size | 16 gauge |
| Fits Models | Honda CT90, CB175 / CL175 / SL175, CB200 / CL200, CB350 / CL350 / SL350, CB360 / CL360 / CJ360, CB450 / CL450, CB500T, CB500K, CB550K, CB550F, CB750K / CB750F / CB750A (1965–1978) |
| Sold As | One pack: 1 male housing, 1 female housing, 7 male and 7 female brass spade terminals |
Note: The housings and terminals ship loose, not assembled. This is an aftermarket connector, similar to the factory one.
Model-Specific Notes
- CB500K, CB550K, CB550F: The original rectifier plugs into the main harness at the bottom 6-pin connection on the electronics tray, and our CB500K / CB550K / CB550F regulator / rectifier plugs into the same connection.
- Early CB500K0: These bikes used rare round-pin connectors for the stock rectifier. To fit our regulator / rectifier, replace both the connector on the main harness and the one on the new unit with this 6-pin connector. The spade-style connectors are longer than the original round-pin ones, so they won't fit the original mounting plate.
- CB550K (1974–1976), CB750F (1977–1978), CB750 K3–K8: The fuse box plugs into a six-pin connector. If the connections on the original (female) harness side are loose, replace that six-pin connector when you replace the fuse box.
- CB360 / CL360: A 6-terminal connector was commonly used for the fuse box connection.
- CB750: A 6-terminal connector was commonly used for the regulator / rectifier connection.
- Custom harnesses: In some cases Honda used a 6-terminal connector but only 5 of its terminals, so keep that in mind when you build a harness.
What's in the Pack
- Male plastic 6-terminal housing (1)
- Female plastic 6-terminal housing (1)
- Brass male spade terminals (7)
- Brass female spade terminals (7)
That's one extra male and one extra female terminal, because we know installation mistakes happen.
Installation
Difficulty: Intermediate
Tools needed: Open-barrel crimp tool (yes, you will need it), wire stripper, and a soldering iron.
Correct and incorrect open-barrel crimps. Tap or click it to open the full-size version.
- Disconnect the battery.
- Cut the wires where they enter the old connector. Use a wiring diagram for your model to identify the wires, because each one needs to go into the same spot on both halves of the new connector.
- If you're using heat shrink, slide a piece onto each wire before you fit the terminal.
- Strip the insulation and test-fit the wire in the terminal. The bare wire should stick out just a hair past the barrel.
- Crimp the rear tabs around the insulation first, using the larger opening on the crimp tool. Then flip the terminal and crimp the inner tabs around the bare wire. Give the inner crimp a second squeeze with the flat at the end of the tool.
- Solder each connection for a permanent, reliable hold.
- Push each terminal into the housing until its small locking barb snaps into place. Male terminals go into the female housing, and female terminals go into the male housing.
- Add a dab of dielectric grease, shrink the heat shrink up to where each wire enters the connector, and reconnect the battery.
Double-check every position before you push a terminal in. Once installed, the terminals are very difficult to remove.
Our wiring harness electrical connector video covers stripping, crimping, soldering, and heat shrink. The little terminals in the plastic connectors crimp on the same way as the bullet terminals shown in the video.
Frequently Asked Questions
Does it come assembled?
No. The plastic housings and brass terminals ship loose. If your old terminals and wires are clean, you may be able to reuse them in the new housings, but that's at your discretion.
Will this replace the round-pin rectifier plug on my early CB500K0?
Yes. Cut off the old round plug and re-terminate the harness wires into one half of this connector, then do the same on the new regulator / rectifier with the other half. Keep each wire in the same spot on both sides. The new connector won't fit the original mounting plate.
My bike has a brown plug with no lock. Can I replace it with this?
Yes, with the white connector that matches its pin count, and we recommend it. We don't sell the brown plug used on earlier Hondas. It's a friction-fit connector with no mechanical lock, and over time sun and heat cycles let it vibrate apart. A zip tie around it will hold it together, but replacing it with the later white square connector is the better fix. The white connector has a mechanical lock that holds it together. We carry the white connectors in 3-pin, 4-pin, and 6-pin sizes.
How big is it?
The male housing measures about 1/2 in. tall by 1 in. wide and 1-1/8 in. deep.
Is this an original Honda part?
No. It's an aftermarket connector, similar to the factory one, and made in Japan with brass spade terminals.
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Last updated: October 2026
