Blown fuse - any ideas???

Hi,

I stupidly jet washed my FZ6 last weekend, as the frame and hard to reach bits were filthy.
On the next ride I lost all power and all info from the display and had to be recovered.

Once home I worked out that fuse 5 was blown, and it kept blowing when I replaced it. I can see it spark when the new fuse goes in, either blowing immediately or when the ignition is turned on.

I've left the bike for 5 hot days to dry out in case this was the problem but it's still doing it now so am a bit stumped.

Fuse 5 is the backup fuse for the odometer, clock and immobiliser system

Could it be a bad earth somewhere??? Any other ideas? If it helps, I also had to replace the display unit last year so some of those connections may have been a bit more delicate than they originally were.

Any help or ideas would be much appreciated, thanks

You probably got water in a connector somewhere, I would start at the speedo and work my way back, unhooking the connectors, cleaning them and put some dielectric grease in them

I'm not sure of the rating of the fuse - but if you say fuse 5 controls the odometer and such, and you had replaced the display the prior year - this leads me to believe you have a short in your speedo display - whether its caused by improper wiring or perhaps water in your connections as chevfazer said. 5 days should have dried it out by then.

Your fuse will open (or blow) when more current passes through than the fuses current rating. This to me means one thing - you have a short. If you had an open, or a faulty connection - current cannot travel through without a complete path. If something is shorted, think of it as being "skipped over." Since your resistance is therefore lower, your voltage will remain the same and current will increase. This leads me to believe you have a short somewhere. Perhaps 2 of your wires are touching, or water in your speedo somewhere.

I would look for a wiring diagram or a schematic and go to town on your display unit looking for something of such nature. If you can't pin it down to a certain short - trace your diagram and try to re-construct it strictly to how the diagram depicts.

Another though - when you replaced your fuse, you positive you bought the right fuse? There's 2 ratings, one for run current and one for surge current. If you bought a fuse rated for 5amps run current, that does not necessarily mean the surge current is the same. Make sure the surge current rating of your replacement fuse is the same as your original. do NOT go and buy a larger fuse thinking you can pass more current through - or you will have major problems.

Hope this helps.

A easy way to check for a short is unplug instrument cluster then install fuse. If fuse does not blow then you have a short inside cluster. You can do the same for anything else on same circuit.

The best way to isolate the problem is to install a test light where the fuse goes..(A 12 volt light with two leads is all you really need)
Or a volt meter will work too if that is what you have.

If you have a short in that circuit the light will lite up..(or it will show 12 volts)
Then methodiocaly disconnect one connection at a time, when the light goes out, that will be the circuit that has the short..

WillFZ6 said:

Fuse 5 is the backup fuse for the odometer, clock and immobiliser system

Click to expand...

If that is correct that might explain why you had to walk home. The backup power to the odometer is very low current. However the immobilizer circuit IDK as we don't have that in the US and I have no schematic for it. But all of the advice above is good. The test light is the best and easiest. Disconnect stuff until it no longer lights and then troubleshoot that component.

Off hand I'd say unplugging the cluster is very easy and would quickly eliminate it from the mix.

You could place an ammeter in where the fuse is, but if its a dead short you blow the fuse in your meter instead (pending on its rating).

Does anyone know how the immobilizer works on these?

Water would have to have a lot of salt in it to cause a 5 amp fuse to blow at 13 volts.

Just off the top of my head I would say as others have said, look for a dead short. I would suspect wire that bends in the harness near the steering. Look at your steering stops at the frame a triple to see if a wire has been pinched. Don't keep replacing fuses until you have found the short.

FinalImpact said:

If that is correct that might explain why you had to walk home. The backup power to the odometer is very low current. However the immobilizer circuit IDK as we don't have that in the US and I have no schematic for it. But all of the advice above is good. The test light is the best and easiest. Disconnect stuff until it no longer lights and then troubleshoot that component.

Off hand I'd say unplugging the cluster is very easy and would quickly eliminate it from the mix.

You could place an ammeter in where the fuse is, but if its a dead short you blow the fuse in your meter instead (pending on its rating).

Does anyone know how the immobilizer works on these?

Click to expand...

I believe the immobilizer uses a chip in the ignition key that ecrypts a code to the unit. If the ID is correct the immobilizer allows the bike to be started.

thanks for the all the quick replies, much appreciated.

i'll go and disconnect the speedo then and go from there, i'm quite familiar with the wiring from having to replace the unit last year so fingers crossed its something obvious.

i'll keep you updated, thanks again for the help!