Hi all, I'm new here, from the Gold Coast, Australia. I have a 2007 CBR600RR. Flawless bike except for one issue...

I have a small issue with my bike in that the low beam (right headlight) won't turn on, however the high beam (left headlight) turns on and off as normal. Infact, the whole bike works as normal aside from the low beam headlight.

Don't worry, I know both are not supposed to be on at the same time! The low beam is not shining at all, not even a tiny bit.

The things I have tested so far are:

• Checked fuses next to the battery; all good.
• Checked headlights bulbs; all good.
• The voltage at the low beam headlight with the ignition on is zero volts
• Swapped some of the relays around; headlight relay seems okay.
• Checked over the rest of the bike; everything else works as normal.
• I have tested the start switch; works good.
• I haven't been able to take apart the left side switch block fully, but the wires seem to test okay, doubt it is related that much!

The circumstances when it failed were; I had parked the bike for about 15 minutes (so the engine was still warm). I went to restart the bike and the bike turned on fine, however a second after starting the low beam turned off. I road home with high beam and have been doing that for a while.

Any help will be appreciated! I have attached the wiring diagram too!

The best way I can understand the wiring diagram is:

1. Power goes from the battery to the ignition switch
2. Power then goes back to the fuse box (to 4 fuses)
3. Power goes through the headlight fuse, branching to the relay and also to the engine run switch (Note: When pressed, the run switch turns the lights off to give the starter more power), hence why it does this.
4. Then power goes from the engine run switch to the LOW BEAM headlight, and also to the left hand switch block.
5. If high beam is ON, power then goes to the headlight dash light, and to the headlight relay.
6. Power then comes back from the headlight relay to the HIGH BEAM headlight.

So if my understanding is wrong please let me know! Oh, and it shares a ground with the high beam, horn, fan and side-stand switch and those all work so I'm assuming it isn't a grounding issue either?

 

A bit more sleuthing reveals that the headlight unit itself is fine (solid continuity on those connections). And I put my test light on the blue and white wire that connect to the starter switch, and it is alight with the ignition ON (good) and goes out when the button is pushed (also good).

So as far as I can tell, the blue and white wire from the engine run switch to the headlight has a break in it? Seems pretty random to me? I have replugged that connector with no success. I guess perhaps the connector wire has loosened..... Gah!

 

Hey, it sounds like I have exactly the same issue. Did you find a solution?

Timmy.

 

@KICKERMAN any resolution on this?
@Topmonkeyboy and anyone else having this problem, it's a 5-minute fix with multimeter.

First, bench-test bulbs off bike. He did this 1st and got easy test out of way.

Next, he gave all steps required to fix problem, just need to pull out multimeter since we're not Superman and can't see electrons flowing in wire. But DO NOT make ANY assumptions with wiring. Such as ground-wire being good. There's a separate section of wire that branches off from high-beam socket that could be broken anywhere in between. So don't be lazy, take the 5-minutes needed to fix this!

Next, pull out meter and measure resistance between ground-terminal of bulb-socket and chassis-ground. Ohms = ???

Finally, after confirming ground wire is actually good, follow path of electricity from battery all way to bulb-socket, measuring voltage at each and every junction. Where power stops, shows problem is between that point and previous junction that did have power. Simple!


So measure voltage at each point listed above. Write them down,
Volts 1 = ???
Volts 2 = ???
etc.