Headlight fuse blown & again

[degsy24]

Hi, my first time on this forum. This problem sounds close to my issue. I have difficulty starting my 2016 TS. Turn on ignition, everything seems ok, instruments sweep and starter relay clicks but nothing happens on starter button. It will eventually start from anything to 2 to 20 presses with switching on and off in between. Occasionally it even starts first time (rare). I have changed the battery and starter solenoid. This week I found the right side dip headlight was off and the entire headlamp unit had misted up. I just thought the bulb had blown. On taking off the rear cover I found that I only had one spade connector attached to the bulb. The other one had completely burnt out and the black block connector which encloses the 2 spade connectors had completely gone (burnt) causing the misting of the unit with the smoke. The spade connector was missing and all that was left of that one wire was a tangled stubby mess of wire. Surprisingly no fuse blew and the wiring to the other dip headlight and both high beams are fine as are the daytime driving bulbs.

I still have the starting issue without the bulb attached by the way so probably unconnected.

Could a faulty bulb have caused this burn out? It has been in there for some time and is not a new fitment.

I have a new wire on order (after market as it was all I could get) but it looks as if it will be hard to fit as all fairings etc will have to be removed. Also it looks as if the dip part of the wires pass through a small rubber grommet and will not fit through with connectors on each end. has anyone done this job before or experienced similar issues?

I managed to clean up smoke damage (sort of) on the inside of the lenses using a damp rag on the end of a screwdriver pushed through the 3 bulb holes.

[Paul2bikes]

Strange your 20amp fuse didn't blow, I blew 3 while testing mine. With the fuse gone, my starter did zilch.

[Paul2bikes]

Originally Posted by degsy24

Could a faulty bulb have caused this burn out? It has been in there for some time and is not a new fitment.

If the bulb shorted out like mine did, it should have blown the fuse. Have you checked the fuse & sure it's a 20amp, not greater.

[degsy24]

I've had the bike from new (31,000 miles) and they are the original factory fuses. Like you, electrickery is a mystery to me. The bulb itself hasn't blown internally but could a loose spade terminal or one that had broken loose with vibration etc have caused a build up of heat so much that it melted the connector and a bit of the wiring, strangely without melting the wiring to the adjacent spade connector?

I too was amazed the fuse didn't blow before such damage was caused! All the other lights still work perfectly and show no signs of wiring damage. Although I haven't yet taken the front end apart, I suspect that they are all connected to the loom via the same connector block. This is why I am concerned about how I can fit a new wire just to the right hand side dip bulb as that one wire seems to pass through a tiny grommet filled hole in the headlamp shell. Will I have to buy a whole right hand side headlamp, or worse the whole unit with the wires already in situ. I hope not. Probably just have to do a bit of cutting and crimping/soldering once I can pass the wires through the small hole but it is a very short wire with not a lot of room to work on it once it is inside the headlamp unit. Whatever the cause, I hope it doesn't just repeat once back together.

Like I said, I am unsure if this is also the cause of my starting issue. Could be a coincidence that this happened at the same time. My mechanic reckons it can't be connected as the headlights on my model (other than the daytime running lights) do not come on until the engine is running.

Frustrating!!

[Paul2bikes]

Yours must be a later model than my '14 gen1, my lights are on until I press starter, then back on as it starts.

Sounds a pig of a job to repair the wiring in that space, bad enough changing a bulb, unless you got hands like a piano player.

Good luck with it, keep posting for reference, might help next person to suffer same.

[ZuluTiger]

At the risk of stating the obvious (for some), no fuse will blow for a bad connection. A lug or bad joint develops heat as current passes through it and could even melt and catch alight without a fuse blowing. The reason is that even very low current through a high resistance creates heat and may well be far below the threshold for the fuse to blow. If, after the fault develops, the wiring becomes grounded or shorted (pos to neg), it may blow the fuse. It would depend on how much resistance is included in the path.

[degsy24]

Thanks for that. In my ignorance of all things electrical I naively thought that a build up of heat would trigger the fuse to blow to protect the circuit. Every day is a schoolday.

I guess I was lucky not to have a fire or at least melt a lot more of the surrounding plastic. I guess that once the spade connecter had melted away from the tang on the bulb the circuit was broken so no more heat/melting occurred. My suspicion is that it was the bulb failing that caused it rather than any wiring fault, which could reoccur once replaced, since the rest of the headlight unit wiring appears to be fine.

I will update later but I have to wait for 2 weeks for the wiring to be available as it is apparently on 'back order' at Fowlers (UK) via my local mechanic. Apparently the part is only £4. I will be doing it myself though as I can't even imagine how much labour costs would be involved to dismantle the front end etc. Although I have never before crimped or soldered wiring.

While it is apart I will be taking tank off and checking/cleaning the main earth at rear of the engine and possibly cleaning starter motor in an attempt to solve my starting issues. I will also fit new headlamp and starter relays just in case.