'PARK' fuse keeps blowing

[the big read]

Hello all,

About 2 weeks ago my indicators and rear running light (PARK) fuse blew. It was the first time it had happened since owning. I changed it with the spare.

Last night as I started the bike after work I noticed that it had gone again. A trip to Halfords later and I bought a new fuse and put it in. Great.

When I left work just now, I noticed that it had gone AGAIN. I don't want to put a new fuse in it every day, so I am just wondering if anyone else has any ideas about where to start investigating, and what to look for?

I will try and have a look tomorrow, checking the wire from the handlebars to the back. It has been raining, but no more than any other day.

All lights are stock.

Anyone any ideas?

Thanks.

 

[Motogiro]

Good day!

There are a number of places you could experience a short that would effect this fuse.
That running light circuit feeds:

The the 2 front running lights which are usually shared with the 2 front directional lamps.

The directional lights, front and back.

The tail lamp. This lamp has the brake light(yellow wire) and running light(blue wire) filaments.

The license plate lamp.

I would start by inspecting any wiring that has been modified. Is there any aftermarket lighting on the bike or is it stock?

 

[the big read]

Thanks for a quick and knowledgeable reply.

The lighting is completely stock.

Once I put in a new fuse, all lights affected (indicators, rear runner, and numberplate) all work.

One thing I have noticed is that the running/brake light cluster is slightly loose. I recently removed the top box rack, which ever so slightly provided cover for the rear cluster. I wonder if rain is getting in through it now it's removed. When I say it slightly covered it, I do mean very slightly.

 

[Motogiro]

Thanks for a quick and knowledgeable reply.

The lighting is completely stock.

Once I put in a new fuse, all lights affected (indicators, rear runner, and numberplate) all work.

One thing I have noticed is that the running/brake light cluster is slightly loose. I recently removed the top box rack, which ever so slightly provided cover for the rear cluster. I wonder if rain is getting in through it now it's removed. When I say it slightly covered it, I do mean very slightly.

It's very unlikely that there is a problem with rain water blowing a fuse and the tail light assembly has rubber mounts so that assembly sort of floats on those mounts.
I would check around the area where you had the top box mount to see if there was an inadvertent compromise of a wire. Twist and pull to get the tail lamp socket out and carefully inspect the lamp itself. There have been cases of lamps creating a dead short internally. IIRK the wiring for the lights travels on the left side of the FZ6. Remove the left plastic pod below the seat to inspect the lighting wires. Blue with a red tracer and blue are the running light wiring colors.

The next time you replace the fuse fire up the bike and see if the fuse blows when you put the either directional on. If it does you've narrowed it down to that part of the wiring. The front signal stalks have dual filament lamps. One filament is the running light and the other is the directional light. Pull those lamps and inspect them.
Please let us know how you're progressing.

 

[the big read]

It's very unlikely that there is a problem with rain water blowing a fuse and the tail light assembly has rubber mounts so that assembly sort of floats on those mounts.
I would check around the area where you had the top box mount to see if there was an inadvertent compromise of a wire. Twist and pull to get the tail lamp socket out and carefully inspect the lamp itself. There have been cases of lamps creating a dead short internally. IIRK the wiring for the lights travels on the left side of the FZ6. Remove the left plastic pod below the seat to inspect the lighting wires. Blue with a red tracer and blue are the running light wiring colors.

The next time you replace the fuse fire up the bike and see if the fuse blows when you put the either directional on. If it does you've narrowed it down to that part of the wiring. The front signal stalks have dual filament lamps. One filament is the running light and the other is the directional light. Pull those lamps and inspect them.
Please let us know how you're progressing.

Today I took the rear off of the bike and inspected the wiring.
Very quickly, I noticed that the armoured cable running from the loom to the rear light cluster has been crushed.

The armour has split and the blue wire inside has also crushed and split. It had continuity most of the time, but if I bent the wire then it would drop connection.

I soldered the wire back together (my first ever solder I might add) and taped the wire, and then the armoured cover back together and tested continuity a few times to be sure. Absolutely fine. Very pleased with myself.

I do, however, have a problem with the rear running light not always coming on automatically without the need for a tap on the rear cluster. Obviously this is a worry to me as a bump in the road may knock it back out. The fit is firm into the bulb housing so I am at a loss as to why that happens.

I am looking to replace the wiring unit that goes from the rear cluster to the loom.

If anyone has a UK part number for that, that would be fantastic.

Pic of the wiring section I am refering to for reference:

 

[Motogiro]

Great job! Blah

Could be the bulb contacts or filament inside the bulb. Get and OEM replacement because they are designed for the vibration of the bike. That vibration destroys standard automotive 1157 type lamps...

 

[the big read]

I shall do. Thank you for all your great knowledge.

I've ordered a used wiring harness (couldn't find new anywhere) for £10, and will get a new bulb this week.

Edit: it looked to me like the harness had been crushed against the bracket for the top box, which is bolted into the rear subframe, and goes around the exhaust fascia. It has been installed for a long time, judging by the previous owners paperwork. I don't really use the box so took most of the rack off. When I change the harness, I'll probably take the bracket off.