No Lights after heavy session on MX track

14 replies to this topic
  • Follett

Posted April 25, 2002 - 06:28 AM


Hi, spent 4 heavy hours on a track yesterday. Got home and realised lights are not working (front & rear nor brake). Checked bulbs, all ok, checked what connectors I could find. Checked switch on bars, seems ok (kill switch works). Any ideas?

Thanks Rich

  • wrsm

Posted April 25, 2002 - 11:00 AM



Check for wiring loom rubbing through and shorting to earth. Near headstock or behind radiator.

Check for damage on front of engine where wires exit, infact full legth of wire for stone damage.

Remove tank, find the connector at the end of that wire. Disconnect it and check between the yellow wire and frame for voltage when you fire up the bike. If you havent got a tester just use a 12v bulb - it should get really bright then blow. If volts are there its a wiring loom problem or switch or regulator problem. If no volts then the problem between the connector and generator or the generator itself.

Sometimes regulators go wrong and short to earth - disconnect the regulator (silver box on LHS of frame near headstock). Start bike up. Any lights that are turned on will get really bright then blow - better to use a meter with the lights turned off.

Keep us posted - tell us what you find. More info can be had if you do a bit more diagnosis


  • sfc_crash

Posted April 25, 2002 - 03:15 PM


check your fuse, red side. i think.

[ April 25, 2002: Message edited by: sfc crash ]

  • The_Missile

Posted April 26, 2002 - 02:54 AM


Check banjo bolt connectors on top of rear brake cylinder for contact with frame.

  • Quickrik

Posted April 26, 2002 - 03:18 AM


I have got EXACTLY the same problem after this w/es ride. I suspect the connector under the tank has come adrift.

Hey Rich I guess you leg is okay now then if you've been MXing! - We're planning a big rideout south of the PunchBowl this Sunday if you're interested.

  • GPS Dual Sport

Posted April 26, 2002 - 09:08 PM


The yellow wire coming out of the lighting coil is the source of all voltage for the lights. I had this connector under the tank get corroded and cook itself into a non conducting charred lump. It required a new connector to fix the problem. Follow the wires out of the ignition cover up the frame and you will find the yellow wire and where it connects into the main harness.

  • Follett

Posted April 28, 2002 - 08:41 PM


Hi all, thanks for all the advise, will check tonight. Rich

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • Quickrik

Posted April 28, 2002 - 10:29 PM


I checked under my tank, and zaknavage had it, the connector was a black charred lump. Not too far gone thought, a quick sanding and shes as good as new!

Cheers Rik...

  • Follett

Posted April 29, 2002 - 12:04 PM


Hi All, still not found the answer but have some more news. The brake light works if the light switch is set to OFF. If the lights are switched ON then the brake light does not work!. Still neither front or rear lights not working. I have removed the tank and checked every connector I can see. This is very fustrating. Might have to take it to a dealer. I have borrowed a volt meter from a friend but don't really understand how to use it if I'm honest.

Thanks for your help.

  • Buckholz

Posted April 29, 2002 - 12:28 PM


You have a dead short downstream of the light switch. When you turn the light on, all the power goes to ground.

Trace all leads downstream of the light switch, you'll find your answer.

  • wrsm

Posted May 01, 2002 - 10:40 AM


The fat 42 year old is most likely to be correct. Really carefully check the loom - including loom to switch. Run the engine with lights turned on and tank off and work the loom about to see if you get the lights working - then look for the short - probably hear/see it sparking. If no joy there try removing the headlight bulb and seeing if just the tail works, then visa versa cos the bulb may be shorting inside.
Good luck.
Average build 43 year old supermoto and trail rider.

  • Guy

Posted May 01, 2002 - 10:44 AM


WRSM......43?....43????? You must have had a HARD paper round me old mucker! :D :) :D
LOL, Dont send the boys round please, I couldn't resist, I wont do it again I promise

  • wrsm

Posted May 09, 2002 - 11:04 AM



Did you ever sort out the problem?
The suspense is killing me!!

  • Follett

Posted May 16, 2002 - 08:34 PM


Ok, the lights now work again after I replaced the speedo/ODO with the digital trailtech panoram. No idea why this might be as the only wires going into the speedo are for bulbs. Thanks once again for all your help.

  • wrsm

Posted May 17, 2002 - 11:22 PM


Damn, didn't ask you to check for that!!!

Those little bulbs fit into tiny clips that can touch each other if the bulb is removed or if you damage the connector in an off. The tiny clips just sit there in the rubber boot, its easy for them to move about.

Pleased you got sorted in the end.


Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.