® Honda Inline Four
Wire Color Codes
1969~1974

Battery From To
Red Fuse (at start solenoid) Keyswitch
Black Keyswitch Switches, Components   
Green2    Components                           Frame ("Ground")
The section above applies to each of the sections below.
Because of this, each of the following sections begins with the keyswitch.
Headlight From To
Black Keyswitch On/Off, Hi/Lo Switch
Blue On/Off, Hi/Lo Switch High Beam
White On/Off, Hi/Lo Switch Low Beam
Tailight From To
Black Keyswitch On/Off, Hi/Lo Switch
Brown/White On/Off, Hi/Lo Switch (Back to the) Keyswitch
Brown Keyswitch Taillight
Stoplight From To
Black Keyswitch Frt and Rear Stop Switches 
Green/Yellow Frt and Rear Stop Switches Stoplight
Signals From To
Black Keyswitch Turnsignal Relay
Grey Turnsignal Relay Turnsignal Switch
Light Blue Turnsignal Switch Right Turnsignals
Orange Turnsignal Switch Left Turnsignals
Horn From To
Black Keyswitch Horn(s)
Light Green Horn(s) Horn Button
Charge From To
Black Keyswitch Voltage Regulator
White Voltage Regulator Field Coil
Green Voltage Regulator Wire Harness "Ground"3
Yellow Alternator Stator Rectifier
Red/White Rectifier Battery
Start From To
Black Keyswitch Solenoid
Yellow/Red Solenoid Starter Button ("Grounded")
Ignition From To
Black Keyswitch Engine Kill Switch
Black/White Engine Kill Switch Ignition Coils
Blue Points 1&4 Coil 1&4
Yellow Points 2&3 Coil 2&3

Notes:
1. This table stops at 1974 because afterward Honda used a differerent starting system, headlight system, and more fuses. It includes only inline fours because Honda's twins, opposed fours and V4s all use a different type of alternator.

2. Honda's colors for switched power (black) and for ground (green) are opposite most other company's.

3. Honda has from the beginning, and even more so in later years, relied on very few physical grounds, preferring instead component ground loops back into the wire harness for a central ground on the frame. A very good practice which the other manufacturers did not start until quite recently.
1975~1982 Wire Color Codes

                Mike Nixon