Topic: 71 CB500 blown fuse trickle charger surge

[Bluegrass500]

Need some advice on my 71 Cb500....It was on the trickle charger plugged into a GFI wall outlet....tripped the relay (on breaker box on the wall) from an overload and as a result the main 15 amp fuse on the bike blew...replaced it and still no power to the bike?? I used a test light on the battery and the fuse holder and it does go on and off with the key, but no power to the starter or the headlight or the gauges....so a dead bike still?? Am I missing more fuses or what?
 Thanks for the help.....all I wanna do is ride this old bike!

[TwoTired]

all I wanna do is ride this old bike!

imo, if you have an old bike, you must enjoy working on it, too.  There is also an expectation of proper tools, as well.


You have to follow the routes on the bike using the wire diagram.  If something doesn't work, it isn't getting power.  Use the meter (or your test light) to find which device or at which point the power isn't passing.

None of the circumstances you've described lend a clue to where precisely to look.

[Bluegrass500]

agreed.....a year of tinkering has been an adventure.....
where does the power come from to the dash cluster of lights???
even if the bike won't start I'd expect to the green neutral to light to come on ??

thanks

[calj737]

agreed.....a year of tinkering has been an adventure.....
where does the power come from to the dash cluster of lights???
even if the bike won't start I'd expect to the green neutral to light to come on ??

thanks

You have to follow the routes on the bike using the wire diagram.  If something doesn't work, it isn't getting power.

Have you pulled down the wiring diagram yet?
http://manuals.sohc4.net/CB500/HSM500550_11.pdf

[Bluegrass500]

Yepp printed it out and going to trace wires....thanks

[TwoTired]

where does the power come from to the dash cluster of lights???

Br/w wires, sourced at the key switch.

If I recall correctly, the Key switch should have an external wire jumper between TL1 and IG switch posts.

even if the bike won't start I'd expect to the green neutral to light to come on ??

Yes.  If the neutral switch provides gnd. and the Black wires get activated by the key switch.
You have to be in Neutral, of course.

Has your frame been painted?  Have all the electrical connections to the frame been scraped of paint?

[Bluegrass500]

Ok hope you don't mind that I am less then confident with my electrical knowledge...so thanks for all the advice in advance,

When the key is in the off position my test light comes on when probing the red lead on the starter switch...then when I turn the key to the on position it goes out??
Seems backwards in my mind?? or whats left of it...thanks


Bike was in tip top running shape before the power surge blew my main fuse....all stock no paint or anything.

[TwoTired]

Describe your test equipment.  LED or incandescent lamp?

Need to know where you are placing both connections of the test equip.  I don't want to make ANY assumptions.

[Bluegrass500]

incandescent light for 12V
I am using the ground on the frame.....and then probing the wires.... its just a 10 dollar unit that looks like a screw driver hooked up with and ice pick.
thanks hope that helps.

[scottly]

When the key is in the off position my test light comes on when probing the red lead on the starter switch...then when I turn the key to the on position it goes out??

Do you mean the red wire on the key switch? If so, connect your test light to the positive and negative terminals of the battery and turn the key on: if the light goes out, it means your battery is suspect.