Bonneville America Forums Forums Technical Forums General Tech My lights won't work, stuck on the path to why

Hey folks,
I'm new to these forums so I'm sorry if I'm posting in the wrong forum, which I probably am. This is also my first Triumph bike! Anyway, I need some help. And before I start I just want to mention that I know damn near nothing about electricity and electrical circuts. So any time I run into an electric-related problem I panic. Which I am doing now.

I bought my bike a little over 2 months ago. It came with an auxilary lamp kit similar to this one and that's where my problem starts. The lamps worked fine up until 2 weeks ago when one lamp crapped out followed by the other a day or two later. I removed the bulbs and sure enough they were both blown. I replaced the bulbs, flipped the switch and got... No light. Dammit. I checked the bulbs again; the filaments are intact. Checked the switch; the switch seems to be functioning correctly. I checked the fuse box; all fuses are intact. I notice a clicking sound coming from underneath the tank every time I flip the lamp switch, so I go investigate.

Underneath the tank I find that a 30 amp relay is the source of the clicking. Correct me if I'm wrong but I think a relay works like a current-powered switch. When current is applied, the relay trips and activates another circuit. Right? If that's correct, than this relay seems to be working since I can hear it click over when I flip my lamp switch. I remove the relay and crack it open anyway and everything inside appears to be fine. I'm assuming the circuit should go something like this - flip switch -> trip relay -> power to lights. But no juice is getting to those lights.

So now I'm stuck and confused. The bulbs are okay, the switch on the lamp is okay, the fuses are all okay and the relay appears to be okay... So where do I look next?

Your understanding of the relay & light circuit is generally correct.

Your aux lights will probably have a separate feed coming from the battery (that goes to the relay), this will probably have an in-line fuse. Is that ok?

It is unusual for two globes to blow so quickly, then not work when replaced, there may be an underlying fault.

Edit: Oh, and does the bike start and run fine? Main headlight works ok?

Also if the inline fuse is blown (when you find it) that may mean a short somewhere in that wiring loom.

Tried another relay?

Hey fellas, an update for you:

I could not find an inline fuse between the lights and relay or an inline fuse anywhere for that matter. All the wires went down into the fuse box. So I checked all the fuses again and turns out I'm retarded and missed one the first time! Replaced the fuse and the lights came back to life.

I let the bike run with the lights on for a about 10 minutes to see if the fuse would blow again but it held up. As to why it blew in the first place, I'm not sure. Could having bad bulbs possibly cause the fuse to blow? If not, then I think I'll chalk this one up to water getting in the circuit somewhere since the bike was rained on a few days before the lights went and whoever installed the lights chose to wrap everything in electrical tape instead of shrink-wrap.

Glad you found the problem. Must admit I was rather perplexed over this one. Try dielectric grease on all connections to help with corrosion and water related electrical problems. It works!

Make sure the wiring going into the headlight bucket isn't chaffing against the housing. Sometimes the rubber protector that runs around the opening moves out of place.