Low beams quit. Highs, fuse, relay are goid

[rpeters549]

I checked my huge Trophy manual and no help there. I have high beams, but no lows. Fuse is good and so is relay (it does not split the high/low circuit).
Any thoughts where to look? I highly doubt both low filaments just happened to burn out at once.

[brenchley]

Put a meter on the light - you should get some sort of resistance reading.  If it indicates an open, you have a bad light.  If nothing else, it'll help verify the condition of the light.

[rpeters549]

I get that. It just seems quite improbable they both burned out at the same time.

[Coconut]

Edited to add : I recall one Member that reported a Headlight problem that was "cured"
by disconnecting the Main Battery for half an hour then reconnecting it !
It's not clear if this was total failure or just the Low Beams, but may be worth a try !

That fault may have been caused by an internal ECU error, and disconnecting the battery reset it !

See : Headlights not working

Definitely check both bulbs first -
The Low beam terminal is the central one,
and if you look at the terminals with the central one uppermost
the Ground terminal is on the left.

There should be continuity between the Low Beam and Ground terminals.
( And also between the High Beam and Ground Terminals )



If the bulbs are definitely both good, and there is no power at the Low Beam
Bulb connector ( with the engine running !  ), then I would first suspect
a bad connection from the Handlebar switch.

This could be within the switch itself, that you may be able to access by
taking the switch cube apart to check, or may be due to a wire pulled out
from the connector on the end of the Handlebar switch wiring loom,
which is buried away on the left side of the frame needing the Fuel Tank
to be lifted to access it.



This Topic has further information regarding the wiring circuit,
although this was a total Headlamp failure, not just the Low Beam :

No headlamp - NOT the Ignition Switch Wiring Fault


Cheers 

[STJIM]

All the current flows thru the handlebar switch and the relay supplies the voltage to the handlebar switch.  You could have a bad connection in the low beam "pole" of the switch or a bad wire "downstream" from there or a bad connection at the connector.

It's highly unlikely that the low beam elements in BOTH lamps went bad at the SAME time.  And they probably didn't.  But one may have failed a while ago, but wasn't noticed.  But after the second went out, then that was perhaps when the lows were noticed to both be out 

So checking the resistance of the low beam section of the lamps may be not such a bad idea.  If they check OK, then if spraying the switch doesn't help, my money is on a bad connection at the connector.

[rpeters549]

I think I will try the battery disconnect 'reset' option first. Then I will snake in there and pull a bulb if that doesn't work and be sure the bulb is good. If those two tests show all good (no reset success, good filament in bulb) I will check power to the bulb at the wiring that connects to the bulb. If no power there I will dig in to the switch cube.
My high beams work perfect, but I WILL blind people and don't want to do that.
Maybe later today. Right now I am installing the intake manifold on the hot rod. 👍

[rpeters549]

Actually, I may check the switch cube first. The 'I' button isn't working so if I disconnect the battery I will lose all the settings and that will bug me not being able to reset stuff.

[rpeters549]

Got the cube apart and partially disassembled. To clean up he 'I' switch it has to come fully apart.  I see the ball bearing under the button and know not to lose it (I hope. 😳).
The 3 pics are the 'I' switch. How do I get the black part out of the white? I see the lick tab but don't see how it works.