Main Fuse A' Blowing

[squirrel_hunter]

The reason I didn't have SH2 at the AR was the main fuse. After doing the headbearings I intended to take it to be checked over but as I got to the end of the road the main fuse blew. The replacement blew as well.

So finally got round to playing with the bike this afternoon. Visual check shows nothing. I can't see any damaged wires so thought I'd fire it up to see if it was steering position triggering the short. So bike on paddock stand no movement in the rest of the bike I fired it up.

Taking the the choke off the fuse blew again. So I replaced it and now its blowing as soon as it is replaced. So where to go from here?

With no fuse in bridging the solenoid the starter motor turns (this was discovered by accident). With the circuit to the starter motor removed the main fuse is solid and I get lights on the board. So I'm thinking the solenoid? Will swap it over with a spare tomorrow, but I'm after other ideas if that doesn't work or ideas on the best way to track the fault down...

[Sid Squid]

Originally Posted by squirrel_hunter

With no fuse in bridging the solenoid the starter motor turns (this was discovered by accident).

Hahahahahahahahaha! Did you get a fright?

Originally Posted by squirrel_hunter

Taking the the choke off the fuse blew again. So I replaced it and now its blowing as soon as it is replaced. So where to go from here?

If it's only the main fuse that's affected, then the fault must lie somewhere in:

• The output side of the fuseholder in the solenoid.
• The wire from there to the ignition switch.
• The ignition switch itself.
• The wire from the ignition switch back to the fuse board and the pre sub-fuse contacts therof.
• The live branch into the the regulator.

These are the only parts that are solely behind by the main fuse, all the other wiring and electrical components are behind the sub circuit fuses.

Originally Posted by squirrel_hunter

With the circuit to the starter motor removed the main fuse is solid and I get lights on the board. So I'm thinking the solenoid? Will swap it over with a spare tomorrow, but I'm after other ideas if that doesn't work or ideas on the best way to track the fault down...

When you say 'the circuit to the starter motor removed', do you mean disconnecting the heavy wire from the solenoid to the starter motor?

[yorkie_chris]

There is also a permanent live to clocks which may be cause of it.

[dizzyblonde]

red wire nearside of fairing, green and furry in connection blocks, to the side of clocks???.

[squirrel_hunter]

Originally Posted by Sid Squid

Hahahahahahahahaha! Did you get a fright?

A fright? I nearly **** meself, thought the bike was possessed before I realized I was doing my best to hot wire it.

Originally Posted by Sid Squid

When you say 'the circuit to the starter motor removed', do you mean disconnecting the heavy wire from the solenoid to the starter motor?

Yes. If I have that wire from the solenoid disconnected I can turn the ignition on and get the lights on the dashboard without the fuse blowing. Does this point to a fault with this wire?

Originally Posted by Sid Squid

If it's only the main fuse that's affected, then the fault must lie somewhere in:

• The output side of the fuseholder in the solenoid.
• The wire from there to the ignition switch.
• The ignition switch itself.
• The wire from the ignition switch back to the fuse board and the pre sub-fuse contacts therof.
• The live branch into the the regulator.

These are the only parts that are solely behind by the main fuse, all the other wiring and electrical components are behind the sub circuit fuses.

With the multimeter set to its bleeping continuity tester I have tried the following:

• The output side of the fuseholder in the solenoid. - The red wire from the cap of the solenoid to the fuse box.
• The wire from there to the ignition switch. - Thought you meant from that wire to one that the switch gear connects to (there is a red one up at the connector block that has continuity) but I realize I read it wrong and you mean the ignition switch with the key. But I can't workout from the map which wire I've just found.
• The ignition switch itself. - Which wire's do I test here?
• The wire from the ignition switch back to the fuse board and the pre sub-fuse contacts therof. - As above, though I think it will become obvious once I start testing it
• The live branch into the the regulator. - Got continuity from the cap of the solenoid to the reg rec connectors.

I've also swapped over the solenoid with a known working spare I have and there is no change to the fuse blowing.

Originally Posted by yorkie_chris

There is also a permanent live to clocks which may be cause of it.

Which wires in which blocks do I need to check for this?

Originally Posted by dizzyblonde

red wire nearside of fairing, green and furry in connection blocks, to the side of clocks???.

And you've lost me here...

Interestingly the alarm is now playing up. I have it in service mode for the disconnection of the battery but it's not registering once the battery is removed and with the alarm in its normal mode I can disconnect the battery, and it will briefly go off. Its a Datatool Veto. However I would guess that the alarm is a symptom rather than a cause of the fault.

[dizzyblonde]

ok, as I've lost you.

I am in no way saying this is your issue, but its worth checking none the less. I had a spat of the main fuse blowing completely randomly, several fuses a day at one point and I had to carry spares just in case.

Had the bike stripped down several times by Chris, then Matt, multimeters round selenoids, battery, reg rec, everything you could think of, then me and Matt stripped it down again, after the issue began to reappear......then..... hurrah the blonde here started wiggling the wiring loom when the fairing was off.
The wiring loom that is usually placed over the headlights and clock that is. If sat on the bike, hanging off the left of the loom is a set of wires held together with a plastic thingie.
What happened was the rev counter needle started to go up and down randomly...then boink, another blow. On closer inspection of the loom at the big 'chocolate block' connector, it was green, mouldy, particularly the red wire. Closer still, we moved the red wire around again, clocks began to show evidence this was the cause. We took both terminals out of the plastic connector and cleaned all the green crap off.

Its cured it.

Again, it may not be the problem, but worth checking.

[squirrel_hunter]

Dizz - Got you. I know where you mean up by the front lights hidden at the side of the fairing. I've not seen any corrosion around that area but will have another look.

Another update - As it appeared that the starter motor cable being disconnected allowed the fuse to stay intact I thought it might be that wire that needed replacing. So that has now been replaced. And the fuse did not blow. Went to start it but then remembered that the front switch gear and dash was disconnected. So plugged that all back in and it started up.

Then I remembered that the reg rec was still disconnected, the black/ white and red wired block. So I go to put that in and... Bang the fuse goes as I do this. I assume then that it could be either of these wires shorting out or the reg rec itself? Going to consult the map to workout where those wires should go and will report back. But I've had reg recs go before and it just gives a charging issue not a main fuse issue so I am thinking its the wires?

[Sid Squid]

Originally Posted by squirrel_hunter

Then I remembered that the reg rec was still disconnected, the black/ white and red wired block. So I go to put that in and... Bang the fuse goes as I do this. I assume then that it could be either of these wires shorting out or the reg rec itself? Going to consult the map to workout where those wires should go and will report back. But I've had reg recs go before and it just gives a charging issue not a main fuse issue so I am thinking its the wires?

I think you may have found your problem, if when disconnected the fuse does not blow then the fault lies either in the regulator unit itself, or the plug and wiring thereto. It's not unknown for that connector to get hot - if it has melted inside the two connectors may touch intermittently.

The fat wire on the solenoid to the starter is a red herring, it's not fused at all, and if it were firmly shorted to negative pressing the starter button would cause the the electrics to fail completely as the current would flow directly across the battery - it would also get very warm. I only asked in order to clarify as I wasn't sure of what you meant.

[squirrel_hunter]

Yep I'd say its the reg rec. Swapped it out for a spare I have and the fuse is now fine and I can start the bike (well sort of). Also checked its charging and its going in at 13.5 @5,500 rpm.

Did also check the wires from the reg rec connector and continuity sounded fine.

Unfortunately its being a bit funny to start now. I'm getting clicking from the solenoid but no turning of the engine. As I changed the solenoid over I'll stick the old one back in. Also as I removed the starter motor wire the rust on the bolt had me turning the whole stud which came lose at the end. Although I tightened it back up I fear that may have damaged it. So if the original solenoid doesn't work I'll swap the starter motor over for a spare I have and hopefully that will be it...

Thanks for the help.

[squirrel_hunter]

Final update the original solenoid is now back in place and the bike started first time. Success. But I still hate doing electrics.

Now if I could only find some drill bits I could get those indicators on...