try this:-
click
You will need to print out the diagrams, scanned pretty good from a4 paper so you can write on em.
Generally, if the character is fairly complex it's kanji, if its a simpler beast it'll be katakana (the 42 character alphabet adopted for foreigh sounds and words)
Translating the katakana from my Honda Bros wiring diagram character by character gives a literal translation of "hetsudorito" for headlight.. hehe
here's the katakana and hiragana:
hiragana is used for simple expression of japanese words and doesn't so much appear in formal technical writing.
Have fun!
Oh, guessing for the colours site you'll need to install the japanese language support pack for windows, to get the characters to display.
Hope this helps,
Richard