Topic: Main fuse - me no likey the pretty blue lights

[jdigga]

This should be an easy one but I'm not seeing it.

Bike was running fine until I put it on the charger last night, one of those automatic ones.  I'm 99.9999% sure I didn't attach the leads in reverse.

This morning I found the main fuse to be blown.  With the bike off, as soon as I put a new one it, I saw some pretty blue lights at the fuse terminals and the fuse blew instantly.

I poked around the wiring in there and found the harness to the rectifier had shorted such that the red wire was touching a yellow one and melted the harness a bit.  I cut the harness out and rebuilt the connections.  Hoping that would do the trick, I hooked everything back up and poof, the fuse blew again.  Disconnected the red wire and (rather than waste another fuse) touched a screwdriver across the fuse terminals--more sparks.

I'm at a loss.  I was hoping to take advantage of 50 degrees and partly sunny skies tomorrow but I've run out of time.  Can anyone point me in the right direction?

This damn bike! I hate this bike! I hate this frigging bike! Stupid bike! (Name the movie for extra credit)

[paulages]

i don't always follow this advice, but that it why it's recommended to charge the battery off of the bike. i usually just disconnect the positive.

[supersport_CB400F]

Looks like you’ve cooked the wiring system, I’d go for a quick fix and buy a new/used harness and components rather than try patch up. I fixed up my old stuff and it took forever to get right Depends on your experiece with electrics.

[TomC]

Hi Jdigga
     Have you checked to see if you have charged the battery backwards? Your volt meter should go below zero if it's an analog or show a minus sign if digital if you have.
          TomC

[jdigga]

Battery is charged correctly--I checked it with my multimeter.  But just to make sure I'll try the battery from the other bike.

The charger I have comes with the little quick-disconnect pigtail that you can hook up to the battery terminals.  I have it on my 650 and have charged the battery in the bike several times without any drama.

Oh boy, new wiring harness, eh?  I think this bike is becoming a cafe project far sooner than I anticipated.

[csendker]

I have a similar charger, a whopping 500 mA.  But it's stupid and doesn't know when to quit so I have to monitor it so I don't overcook the battery.  I'll plug it in at night and pull it in the morning then check the battery voltage to make sure.  But the quick disconnect is polarized so I can't reverse the polarity...is this the first time you put it on the battery (pigtail) or did you just plug it in for the umpteenth time?  And I'm thinking 500 mA might not be enough to cook the entire harness.  There's a thread somewhere discussing putting a light bulb in place of the fuse.  Light on = short somewhere.  Then you go about unplugging stuff until it turns off: bingo! your short.

[jdigga]

Oh yeah, I read that thread--I think it's worth a shot to try that.

I don't know the rating on my charger, but it's automatic so I can just plug it in and leave it.  Light turns green when the battery is full.  Like yours the pigtail only connects one way.

I've used this charger on this bike I think once or twice before.  The pigtail is on the other bike though.

[csendker]

It was this post by Hondaman --> http://www.sohc4.us/forums/index.php?topic=14079.msg138171#msg138171

[jdigga]

Cool, I have some short-circuit hunting to do tomorrow.  I've been following medic09's harness thread and I hope I don't have to go that far.   

[Faol]

"The Karate Kid". But I'm pretty clueless on the wiring. I use a Battery Tender Junior on mine and have never really thought about it - I guess I've just been lucky!

[jdigga]

Ah, very good Faol-san. 

[kettlesd]

"The Karate Kid". But I'm pretty clueless on the wiring. I use a Battery Tender Junior on mine and have never really thought about it - I guess I've just been lucky!

oh yeahhhhhh !!! Rah rah onthe Battey Tender Juniors - best things goin!

[medic09]

Cool, I have some short-circuit hunting to do tomorrow.  I've been following medic09's harness thread and I hope I don't have to go that far.   

You have my true, deepest sympathies. 

Let us know what you find out.

[jdigga]

Thanks.  It must have been a fool moon somewhere (wow, I just typed that by accident but it's highly appropos), because both of my bikes are down for the count due to wiring issues.

In a last ditch effort to get in a ride, I pulled out the 650.  Got to the end of street and one cylinder stopped firing.  Barely got it back home and it decided not to start anymore.  The only thing I've touched on that bike recently is the fuse box (borrowed a couple fuses for the CB).

Haven't decided what to do next...

Will a 550 harness of the same year fit my 750?

[jdigga]

My luck has turned around--it was the ghetto toggle switch for my ignition causing the short.  Removed it from the circuit and the bike is running again.  I can now turn my attention back to timing and carb tuning (oh joy)!