headlight problem...can u help?

[RedDemonST]

Hey fellas...

hopefully someone out there has had this issue, and can give me a quick-and-dirty answer..

having an American version of an -01 ST, both headlights stay on at all times. Left-side was out--replaced it and everything was working great....for about a month. The left-side went out AGAIN...thought maybe i got a bad bulb...(but the high beam works) Pulled the bulb and it looks OK...plugged in a "known good one" and still...nothing...
checked the fuse...its fine--anyone have this problem? guessing i have an issue in the wiring, maybe?

Secondarily, i flip the high beams on, the left comes on and the right goes out....***?? haven't replaced the right with the known good bulb yet--seems to be a bit tougher to get to than the left (yes i'm able to change without removing anything--Gumby fingers!!)

thanks for the help! :chug:

[MrMoped]

Red,

I only have the '00 ST wiring diagram so I'll assume that there weren't too many changes between the '00 and the '01.

Firstly, you will need a multimeter or at minimum one of those 12v circuit testers (probe-bulb-lead-clip). Remove the connector to each side headlight and test for 12v on High and Low beams.

for the RH headlight the main beam is blue/white wire, the LH is purple/white. The low beam wires are, RH purple/red and LH blue/red.

If 12v is not present at the required terminal then go back to the headlight relays. The main beam relay can be identified by a red identity tag around the wires leading to it and the Low beam has a white tag. If the tags are missing just look for the wire colours as stated above.

Pull each relay out and inspect the terminals - clean off any rubbish on them. Try swapping them around (they are identical) and see if your problems are now the other way around.

If there were major changes in the wiring between the '00 and '01 you may need to get hold of the wiring diagram for your bike. Either buy a workshop manual for yours or try your local dealer - a good one should give you a copy of the wiring diagram.

Once you have the wiring diagram it is a relatively easy process to track down wiring faults/gremlins