Where has my headlight gone?....

[jamezgreen]

Usually ride my bike during the day but was put in a pretty tough spot over the weekend when I needed to drive home across town and my headlight was out high and low beams! Since I had no other alternatives I had to creep home borrowing the light from other cars. Crazy.

So I've had a little electrical drama before, about a month ago 2 wires touched the cylinder head and shorted out. Fixed the wires, replaced the fuses and I was good to go. Thought it would be a fuse issue again but... both high and low beam fuses are fine and took the bulb out and inspected and the filaments look great too. Is there a way to test the bulb straight off the battery or some other test to better diagnose the issue. ( I have a little voltmeter) I've traced the wiring as best I can and don't see any problem areas. Any ideas?

-James

[Easy Rider]

Originally Posted by jamezgreen

took the bulb out and inspected and the filaments look great too. Is there a way to test the bulb straight off the battery or some other test to better diagnose the issue. ( I have a little voltmeter) I've traced the wiring as best I can and don't see any problem areas. Any ideas?

Check the ground....common - connection. That's about the only thing that will kill both .....unless the bulb is bad or both + inputs are bad for some reason. If you have touched the bulb with your bare fingers, you should get a new one anyway.....and don't touch the new one.

Do NOT try to test the bulb outside of a socket; they get VERY hot VERY fast.

Rather than tracing the wires, you need to trace the voltage.......and the ground....with your meter.

[burkbuilds]

You can also check the bulb with the continuity setting on a meter when it's out of the socket just to see if there is a break in the filament you can't see.

[jamezgreen]

Cool, i'll check the bulb continuity then the wires. I noticed the speedo and the high beam indicator light are also out. Does this give any more clues as to where the issue may be?

[alantf]

Originally Posted by jamezgreen

Cool, i'll check the bulb continuity then the wires. I noticed the speedo and the high beam indicator light are also out. Does this give any more clues as to where the issue may be?

Sounds like it MAY be a bad connector somewhere in the circuit. You DEFINITELY need to check if there is a voltage at the headlight bulb connector. If there is a voltage between bulb holder & the bike body, then the power source is o.k. Next, test bulb holder to bulb holder earth. If this doesn't show a voltage, then this neutral is your problem.

If you don't get a voltage between bulb holder & bike body, then it's a voltage supply problem. Start working your way back along the feed cable, disconnecting each connector in turn, & doing the voltage check each time (at the side furthest away from the headlight) Each time you check & get a voltage, re-connect the connector & try the headlight. Just opening & closing a bad connector MAY solve the problem.

[Water Warrior 2]

Originally Posted by Easy Rider

If you have touched the bulb with your bare fingers, you should get a new one anyway.....and don't touch the new one.

A minute deposit of oil from your skin will create a hot spot on the bulb, which will kill it. Wiping off the bulb with a lintless material will work well. Something like a tissue for eye glasses. I learned this the hard way.

[alantf]

Originally Posted by Water Warrior

Wiping off the bulb with a lintless material will work well. Something like a tissue for eye glasses.

Alcohol is recommended.

[jamezgreen]

Turns out bulb WAS fine just another short. Gotta keep those wires clear of all those hot parts! Is the speedometer/odometer display supposed to be lit on these bikes? If so mine isn't........

[5th_bike]

Originally Posted by jamezgreen

Is the speedometer/odometer display supposed to be lit on these bikes? If so mine isn't........

Yes, quite dimly though, you can only see it in the dark.

[alantf]

Originally Posted by 5th_bike

Yes, quite dimly though, you can only see it in the dark.

And even in the dark you can't see the trip meter (or is that just on my bike?)