Page 1 of 1

[[SOLVED]] 1994 CB400 Superfour - no electrical power to bike

Posted: Mon Sep 10, 2018 10:00 pm
by xander
Could do with some suggestions for a poorly bike. '94 CB400 SuperFour.

Key on, hit the starter, instant lights out, gone, nothing. No lights, no dash, no power. There was kind of a click, but nothing loud starter didn't turn.

Tried bump starting it: starts, but runs like hot garbage, sounds like 2-3 cylinders firing, lights are all going haywire. As if it's running off the alternator only. Lights flickering are in time with firing which sort of confirms this.

Anyway, here's what I know so far.
Battery Voltage: 12.9V
Main (30A) fuse: Working
All ancillary fuses (IG, Lights, etc.): Working!
Loom connections are all intact.

Power is getting to the starter relay, but it gets weird here, on the other side of the relay it's also seeing 12V (as if the relay was closed), but the starter is not running..

Anyway, if you've made it this far into my ramble, any suggestions or troubleshooting tips further would be greatly appreciated if you've had this problem before and remember the fix!

I've not dug that for into diagnosis yet but would like to have a few plans ready to go when I get to the garage.#


Re: 1994 CB400 Superfour - no electrical power to bike

Posted: Tue Sep 11, 2018 4:05 pm
by moforockband
Don't start the bike again until you are sure the reg rec is delivering dc current and at the correct voltage. You may destroy the cdi.

Check you have a sound earth, a decent loom and a working battery/reg rec before trouble shooting

Re: 1994 CB400 Superfour - no electrical power to bike

Posted: Thu Sep 13, 2018 4:23 pm
by xander
Uh. Little embarrassing - just a dead battery. But quite unusual symptoms making me think it's something more serious.

Lesson learned - start with the easy stuff!