Basic troubleshooting steps

[NUTBAR]

I have a 2013 Triumph tiger Explorer, problem is my lights have stopped working, I have checked the bulbs, ok. I have checked fuses, ok. I can’t figure out why they have stopped working or what the problem is? Any ideas would be grateful.
Thanks

[GazzaH]

Broken switch?

Broken lamp socket?

Broken wire?

Or just switched off?!

I'd probably check the voltage at the lamp fitting and work systematically back from there towards the battery, or check at the fuse or switch and work upstream or downsream from there. A multimeter is handy but a 12V bulb with a wire will do at a push. Just be careful not to short 12V directly to ground as that will make a bad day rotten.

[NUTBAR]

They usually start when I start the bike? High/low doesn’t work but if I push the pass switch the lights work? No switch to switch off that I know of?

Broken switch?

Broken lamp socket?

Broken wire?

Or just switched off?!

I'd probably check the voltage at the lamp fitting and work systematically back from there towards the battery, or check at the fuse or switch and work upstream or downsream from there. A multimeter is handy but a 12V bulb with a wire will do at a push. Just be careful not to short 12V directly to ground as that will make a bad day rotten.

[Honest Andy]

1. Find your relays and check that they're plugged in nicely. Then pull 'em out and check for corrosion. Lightly grease the connections then plug 'em in again.
2. Stand back and give the whole bike a stern talking to.
3. Try the lights again
4. Repeat step 2 but use stronger language

[NUTBAR]

I can see some relays but I don’t know what they are for? I’ve pulled them out and checked them, all in clean condition. I’ve given the bike a good talking to but it’s being a typical female!

1. Find your relays and check that they're plugged in nicely. Then pull 'em out and check for corrosion. Lightly grease the connections then plug 'em in again.
2. Stand back and give the whole bike a stern talking to.
3. Try the lights again
4. Repeat step 2 but use stronger language

[Honest Andy]

Next I would probably suss out which was the headlight relay and bench test it. Or just test all of them. Then use a meter and a wiring diagram to painstakingly track down the fault, ending up at that headlight bulb that I thought looked ok...

[NUTBAR]

Next I would probably suss out which was the headlight relay and bench test it. Or just test all of them. Then use a meter and a wiring diagram to painstakingly track down the fault, ending up at that headlight bulb that I thought looked ok...

ok have checked bulbs,ok have checked relays/ fuses, ok still no lights?

[GazzaH]

I'll admit up front: I know a bit about electrics but I'm not a vehicle electrician ... so this may be wrong.

The "passing" switch sends 12 volts to the main beam via a relay and fuse, which apparently works ... so there is voltage reaching the "passing" switch and the relay, and the wire from there to the light socket's main beam contact is OK, as is the main beam filament in the bulb. Good news so far.

Because of that, I'm surprised that the low beam/high beam switch doesn't light the high beam filament in the same way. That suggests maybe a problem with the switch itself. Personally, I'd check the voltages at the connector to the switch, which probably means a bit of dismantling to get to it and careful probing with a multimeter (being very careful not to short anything out in the process). With the ignition on, you should find one connection to the switch permanently at 12 V (the input from the battery), and another that is either at 12 V with the switch on high beam or 0V with the switch on low beam (output to the high beam filament).

I presume there is a separate wire from the relays to the low beam contact on the bulb. There is no separate switch for that ... but normally it turns on with the ignition so I guess it is fed from the battery via a relay that is energised by the ignition key. That relay, its 12v input from the battery (unlikely), the fuse (more likely), the wire to the low beam contact on the bulb (possibly), or the low beam filament itself (highly likely), may be broken or corroded. I'd check each of those with the multimeter.

Do you have a wiring diagram for the bike? It should tell you about the wiring of the lights, switches, fuses and relays, including the colours of the wires bundled into the wiring loom ... but if it's an old bike, the colours may have faded especially where exposed to the NZ sunshine, so it may help to peel back some of the wiring loom insulation for a peek inside. A visual check of the condition of the wiring loom may reveal chafing, burnt insulation or mechanical damage if you're lucky enough to be able to see it at the right angle: a strong light and bags of patience helps, as well as carefully removing stuff in the way, maybe using a dentists mirror to check behind the frame etc.