T3 Electrics

Replaced the ignition switch on the T3 but got a couple of the wires in the wrong position, lights etc worked fine but a press of the starter button cut all electric power. Battery is fine, earth is fine, but there are no blown fuses, which I thought was the obvious cause, and the new ignition switch checks out OK. Anyone any ideas to what to check? Ignition switch is now wired correctly, there is continuity between the the battery +ive and the frame but it seems to come to a halt at the rectifier.

Check you have a switched earth from the handlebar switch to the relay and 2 permanent feeds with the ignition on, Â to the starter relay…

I think he means pressing the starter killed all power, where he had some before ~ now none since ~ trying to think how wiring ign switch wrong might blow the rectifier, but I can’t see it…

How are you doing the electrical testing? Batt +V to frame doesn’t sound right… do you mean negative terminal to frame?

Trevor, send me your email address via PM and I will send you a colour wiring diagram that might help. Best wishes Chris

Thanks all
Going to attack the bike with a decent multimeter today, so far I have established continuity from the Battery +ive to terminal 30 on the ignition switch (red wire) and continuity from Ignition terminal 15/54 (brown wire) to the fuse holder. Been cleaning any electrical connector I could find as I worked on other parts of the bike (should have left well alone!) so will check it all again. Will send you a PM thanks Chris

Colour diagram sent

Sorted. After an afternoon spent with a multimeter and decent wiring diagram (thanks Chris) turned out to be the main earth strap. A new one from a car accessory shop! It must have turned its toes up when the starter current flowed thro it and then been a bit hit and miss after that. Found by that very technical skill of wiggling everything and watching what happened

Nice one gents…

How bizarre! Not much of an earth strap then … congrats anyway!

Glad to hear you are sorted

I’ve fixed guided missiles etc by that very method. Don’t let the technical bods fool you into thinking they know better. :laughing: