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fuse blows when ignition is attempted

Posted: Wed Oct 10, 2012 10:46 am
by davidcharlton
This is one for all you bright sparks. Completion nearly achieved, all the electrics work but when I turned on the ignition and earthed one of the spark plugs hoping for a big fat blue spark, instead the fuse blows, It seems like what ever's causing it to blow is drawng a lot of power vertually draining the battery, any and all suggestions appreciated, David

Re: fuse blows when ignition is attempted

Posted: Wed Oct 10, 2012 11:00 am
by BAZ
Unplug the alternator and see what happens.

Re: fuse blows when ignition is attempted

Posted: Wed Oct 10, 2012 11:10 am
by KETTLE BOY
Take the tank off, and check, the connections on the coils. Dissconect that coil, Then try it on the other two. Then if that's not blowing the fuse, connect up that coil again, and if it blows, that's your problem? Could be a bad coil, shorting to earth. Good luck.

Re: fuse blows when ignition is attempted

Posted: Thu Oct 11, 2012 10:57 am
by yeadon_m
Hi David,
+1 on what Baz advises. I recall 'Dan Hatfield' posting on the US GT Yahoo group extensively on problems just like yours. He points out that nothing thats working properly on a Kettle is capable of drawing enough current to blow the fuse. So it must be something odd in the wiring and if for example you just played with the alternator (one of two top candidates for high current draw when defective) my bet is its that. Simply disconnect the plug under the left side panel and see if the problem goes away. If so, and if you have moved the wiring to it, that will surely be the place for a fix.
The only other viable alternative will be a wire whose insulation has rubbed away so that you have a straight short. These can be a PITA to find, but made easier by finding hot wires and worse, melted insulation - so take the tank and panels off, open the headlamp and feel for what gets hot when this is happening.
The momentary turning of the fan isn't a problem - mine used to do that and its a small current draw anyway.
Good luck!
Mike

Re: fuse blows when ignition is attempted

Posted: Fri Oct 12, 2012 10:01 am
by davidcharlton
Well done to those who said it was the alternator. I had done something stupid, hooking up the cable from the points to the alternator connector. It had been so long since I had completed the wiring, I forgot to check the two 4 spade blocks which can be interchanged, well dony lads!!, not so well done me!

Re: fuse blows when ignition is attempted

Posted: Fri Oct 12, 2012 6:21 pm
by yeadon_m
Hurray - good news, Mike
ps: I only got my info from others, so the credit is Baz's and Dan's (in absentia)