Both my 10amp 'indicator' & 30amp main fuses blow when i press the starter button.

Sequence of events....

Riding to work & notice neutral, oil & side stand dash lights + fuel & temp guages not working so i stop & replace the blown 10amp 'indicator' fuse. I go to turn on the ignition ... all good, start the bike.. all good then within 30 seconds the fuse blows again so later that day I ride home with no 10 amp 'instrument' fuse in & no associated dash instrumentation.

I've made the following tests, but found nothing seems obvious to me...

- Rectifier checks out o.k. .. tested the unit with a multimeter o.k. + started the bike with & without it plugged in (still blew fuse)
- alternator o.k. (as above)
- side stand switch o.k.
- oil sender unit o.k.
- neutral safety switch seems a bit twitchy via the multimeter, although the neutral dash light always seemd to come on o.k.

After my above testing, i put the bike back together & replace the 10amp fuse, took for a ride & about 1-2 minuteS into the ride both the 10amp 'indicator' & 30amp main fuses blow so i replace both fuses. Go to start the bike & both fuses blow again as soon as i press the starter button.... push bike back home.

What on earth is going on ? Would a dodgy neutral safey switch be causing this ? It can't be the start button causing this due to the fuses blowing approx 2 minutes into riding ?


My CBR has been running faultlessly, why this all of a sudden... I am at my wits end.

Help PLEEEEEEEEEEEASE ?

 

check the wiring harness for a place that it has rubbed through and shorted to ground.

 

Yeah, i've had a quick check of the looms. There is rubbing going on but not enough to wear through to bare wires.

I'm going to start testing every wire for bad earths.

Thanks for your reply !

 

+1 on a short!

Rather than a multi-meter, I'd hook up a 12v buzzer (bike horn?) in series with the battery with a croc clip on one end and a probe on the other. That way you can put the clip on the main earth and probe the suspect positives with one hand while you wiggle the harness around with the other.

I wouldn't put a croc clip both ends though because, if you found a major short to earth, you'd melt the wires!

I hope this makes sense?? I wouldn't be worrying about bad earths, rather a short to earth on one of the positive wires.

Good luck mate. That sort of crap is very frustrating.

Mark off the wires with tape as you check them so you don't go around in circles.

Cheers,

Dave.

 

Like they say, you have a short. What is a short? Current flows directly to ground without the resistance of a load. A wire from the positive terminal of the battery to the component has touched ground. Electrical problems frustrate the most experienced of mechanics because it's something you can't see, touch or feel.

According to my wiring diagram, the Black/Brown-stripe wire goes to all of your mentioned components. That wire has touched the chassis or a ground wire. Or as what happened in my old GS1000, the ground wire and power wire touched in a connector. Trace that wire and you will find the problem.

By the way, I like the color-scheme of your CBR. What year is it?

 

Thanks for the feedback guys.

Dave, thanks for that ... I'm using one of those multimeters with a buzzer on it & it shure does make the job a bit easier.

Thanks Slowpoke, mines a '91. I also have a hunch on the Black/Brown-stripe wire, couldn't see see anything obvious from my first inspection so started tracing various power wires last night.... need to get my head around the circuit diagram !.

I'm hoping it is just a short... man i hate electrix stuff

 

No worries. You're on to it by the sound of things. With the multi at least you can hook it up and wiggle the loom about to try and make it short.

Intermittent faults are a real PITA!

 

Check to see the wires arent melted at the main fuse, mine would blow like that since they grounded out. Got another set of wires from the salvage yard. Now good as new and no blown fuse.

 

I agree. The fact that two fuses blow, I would think points to a short of some kind.

I have seen the wires going to the start button short against the bars (clip-ons).

That's an easy one to check. Pull the starter/kill switch pod and look under there. See it the hot wire is missing insulation.

 

My 'spares' CBR i had just bought had a similar prob when I was attempting to get it going some months back. I found where the loom connects to the starter solenoid was badly melted due to a poor connection creating heat. I only found it when I removed the rubber protector boot and unplugged the connector. It keep blowing a fuse up the front on the panel and the 30Amp one at the solenoid.

easy check, unplug at solenoid, inspect wires, if not melted, try starter button and check for voltage, if no blown fuse, it's somewhere there. good luck.

PS. oh, don't do what I done, use the incorrectly rated fuse (read as 'bit of wire') it creates, um......er.......issues shall we say