Short circuit!

[psychlist]

HELP!!!!!!!!!! :o

Monica's in trouble and I can't fix it :(

Took the carbs apart and fitted new jets at the weekend (I'm really proud of myself doing that bit :D ) but when I put "everything" back together it didnt work! I have replaced the ignition circuit relay cos it was buzzing when I turned the ignition on, and Phil H from Pulborough came round last night and, after spotting an earth lead from the coils that I hadnt reconnected spent another 3 hours trying to find a dead-short to earth in the ignition circuit. He's checked all the "operating bits" with a fluke meter but can't find the dead short!! All I did was take off the airbox to get at the carbs and now I 've got a dead Desmo Due race bike with a trackday on Monday!! :eek:
What bits should I check peeps :confused:

[rich]

Hi there

Need more info

Does it turn over?..Has it a spark?


"Dead short on ignition side!!" (Put your ICU's in an other bike to see if they still work :eek: )

Rich

[Unit 18]

Check whether one of the poles from the starter relay is touching the cylinder head, they can be very, very close.

[psychlist]

Rich - since I replaced the main relay it doesnt do anything at all, not even getting the nuetral or oil warning lights glowing! Before I replaced the relay I got them lighting up when I turned the key to on but no response at all on the starter button, then if I pressed the "kill" switch the warning lights would all go dim :(
As I said, now I don't get any response from the lights or switches when I turn the key to on and there is a short to earth somewhere on the main circuit!

U18 - Thank you, something I haven't checked ;)

[rich]

I take it that all was well B4 you started with the carbs?

I know it is obvious but this "short" must have been built in

during the works.

I still feel that you need a mates bike along side, to check like for like on any

items you have touched

And to swap bits over etc

also try to find the short in the ...Dark... (you may see an arc)

Good luck

rich

[stef]

has the short completely drained your battery ? this could happen in a very short time, if you have a complete short circuit.
unplug one terminal of your fully charge battery, and check how much current you are draining with everything switched off.. it should be very low.
(unplugg red cap, place A meter between battery red and bike red.)
then try again on the on position.

i am not sure of the exact reading, but even with ignition on, you should only be draining a few tens mA, for the dash lights..

if that reads very high, disconect every single electrical bit you can on the bike, and plug them back in one by one until you find the culprit.

[psychlist]

Thanks fellas, will give it a try tonight :o

[psychlist]

Took him a while but traced it to a dodgy diode actually IN the main circuit relay grounding out!!! Broke it off and the whole thing runs beautifully, even the revised fuelling from the new jets I fitted in the first place :D

Wahey!!!!!!!!! :burnout:

[Phoenix]

Phew - glad Monica's up and running again Paul :)

[psychlist]

Thanks Lin...........................nice avatar ;)

[Phoenix]

:lol: Thats me doing Ian on the inside at Castle Combe - I wish! :D