Promptly Blowing Main Master Fuse

[ActionStarCBRxx]

A few months back my bike burned up the connectors to the main fuse. I decided to replace the wire harness and take care of several issues at once that I had neglected. (Oil/ dash lights and back dash/ CCT / Tyres). I did replace the main fuse/Solenoid when I did the wire-harness as well. So there are no cuts in this harness.

I decided to replace the wiring harness to make sure I had a clean start. I finally got the new harness in but the bike still blows the main fuse as soon as I turn the key to the on position. I do know that the ignition is always defaulted to on and the kick stand was down. I have only attempted turn the bike on the one time since the issue started a few months back.

I did a brief look at the manual and there is a reference to all the components that are in that starting loop. IF I read it correctly it was the ignition switch, the kickstand and the starter (I dont recall if the fuel pump was in that loop?). So I know I need to grab the voltmeter and go to work there.

Is it possible that when the plug burned that some other component was shorted and is causing this? Which would be the most likely culprit to start with?

Correct me if I am wrong... but is whats happening is that something that is hot is either touching a ground, or a relay/component is allowing electricity to pass across wires that should be grounded? So what I would see when testing continuity (without power to battery) is a situation where there should be continuity but it wont be there or the opposite, there should not be continuity but there is?

[rockmeupto125]

You have a dead short to ground. That sucks.

After a quick visual inspection for anything obvious, I would assume that a new harness has no faults.

This is what I would do.

Disconnect the harness from EVERYTHING except the positive battery terminal. Then place a voltmeter from ground (the frame) to your negative battery terminal. Reconnect everything one by one until you see the meter jump, indicating a completed circuit to ground. That will isolate the circuit that's faulty.

I'm sure there's more eloquent ways, but this should work.

[CALCXX]

FWIW, disconnect the R/R and try it again.

When the R/R shorted on my 98xx it blew several 30A main fusses before I found it.

The R/R had a small burnt hole it showing what happened.

Try it?

[ActionStarCBRxx]

Thank you gentleman for the ideas. I apologize for not replying sooner... but I havent had much time to work on the bike. I unplugged everything as suggested and execpt for the starter and it was still blowing the main fuse.

I took the starter off and found that there was continuity between the brush post (where the cable connects) and the outer cover. I went ahead and ordered another starter at this point from ebay. That starter arrived and it too showed continuity between the post and the outer cover.

So I took my starter apart and found that the brushes that connect to the c shaped thing are 3.5mm. The book states that the service level are 4.5mm. Also the rubber that is the first layer between the brush terminal post and the outer case was worn and brittle. So that explains the continuity between the post and the case. I did not have any ugly burn marks on the commutaror bars and there was no continuity from the commutaror bars to the the armature shaft. So it looks like the shaft is still good.

The question now is the starter rebuildable by replacing the rubber/insulaters/washers on the brush terminal post and replacing the four brushes?

Thanks!

Kelly

[rhubarbray]

Not sure if the XX is a two pole or a four pole but you`ll need something like this.

http://www.electrexworld.co.uk/acatalog/SMBK147.html

Honda has them too, but it doesn`t appear to be a kit. You`ll have to buy individual parts.

http://www.mrcycles.com/fiche_section_deta...amp;fveh=164533

Not expensive and not hard to do. If the commutator is grooved or burnt, take it to a friend/shop/someone and see if they can clean it up on a lathe. Do not remove too much or you may have to undercut the insulator segments again. Not difficult, just time consuming.

Ray

[ActionStarCBRxx]

Excellent Thanks!

Is there a trick to getting the brushes back on? I was tempted to undo the coiled springs... but then I was worried I would never get it back on. The brushes are a bugger to get all four on at the same time. I worked on them for an hour at the kitchen table before giving up.