Hi All, my CB400SF Hyper-VTEC (99) cut out on me a couple of days ago. It went from fine to electrically dead just like that, in traffic.

I got a chance to investigate today and the main fuse was blown. I fitted a new fuse and although the bike now powers up, there's a constant drain on the battery. I removed all the other fuses and still measured a 2 amp current draw on the battery, even with ignition off. That's 24 watts going somewhere so I worked around the bike looking for heat and found it in the reg/rec (which makes sense, as all the fuses were out).

My question is: is this a failure mode of rectifiers or should I be looking for something else which caused the reg/rec to fail?

Thanks

Barny

I've got a '95 Super4 VersionR and this day last week my bike wouldn't turn on, electrics totally dead. Main fuse was blown and every time it was changed it blew again, even with the bike off. Turned out to be seriously corroded wiring on the connector block of the Reg/Rec which had caused it to melt into place and more than likely destroy the Reg/Rec too.

I've just replaced both over the weekend and the bike was running fine on the way to work this morning.

Thanks for the feedback! I've got a new reg/rec to go on, but I'll do a thorough check of the wiring condition before I assume all is well. It'd be a pain to go through another one!

Barny

Hi, do you have any feedback on what you found to be the cause ??

and while im here ,assuming you are on about a cb400 superfour...can you confirm what battery you use ?? cheers

It was the reg/rec in the end. I fitted a cheapie one from eBay and its been fine ever since. The cheap ones don't have the greatest reputation for reliability either, but its a sunny day bike for me and doesn't see many miles, so I figured it was worth a gamble.

I'll check the battery tomorrow night when I'm back home