Topic: Electrical Sytem Dead

[DeLuxe]

Hi. Sorry to post the impossible, but here goes:
I have a CB400f. Replaced the indicators on the front end, they flashed on together (both at the same time), then the flasher unit made a Grrrrrrrrr, sound then complete electrical failure.
Replaced the fuses - even though they haven't blown. Nothing. I tun the key on, and nothing works. Nothing. battery is good. Wiring looks good. taken the whole birds nest out of the headlamp and checked everything. looks ok to me. I've become one with the wiring diagram in the Haynes manual.
I don't have a clue. Something has blown, but what? Do I have to replace all the rectifiers, etc under the side cover?
Anyone had anything even vaguely similar happen to them? I've trawled this forum for a couple of hours, but haven't found anything similar.
Thanks for reading this.

[bryanj]

Get a voltmeter and start at the battery
Has the battery got 13Volt--if not replace or charge

Now put the negative meter lead onto the frame where the earth lead bolts on--should read bat voltage

Leave the neg meter lead where it is and start checking for battery voltage at the following places:-

Red lead into ignition switch--If OK

Turn ignition on and check at black outlet wire--if ok (which i doubt)

Keep followuing the black power leads till you find the problem


Hope that helps
Bryan

[DeLuxe]

Thanks, I suspect you're right about the switch. I'm probably fooled by the fact that the switch is brand new - and so I don't suspect it. The connector block it's plugged into is 30 years old though...
I'll get the VOM out and run your procedure. Let you know how it goes.
I did find a post that suggests a similar problem, but the fault was a blown "BRIDGING FUSE next to the rectifier", which had blown because the owner had a 25 amp fuse installed in the fuse  block instead of a 15 amp one.
Thing is, I can't find this bridging fuse...so I've been chasing a red herring.
Thanks for the reality check.

[78CB750F1]

DeLuxe - I had a similar problem on my CB750 when I changed the flasher unit - it shorted somewhere and I am still chasing it, but the total shutdown problem was due to the main 15amp fuse.  I replaced it and it still didn't work - turned out it was corroded connections on the fuse box.  May be worth cleaning up the fuse connectors...