Newbie mistake- now no headlight power or spark

Well,I hope I didn't really screw this up...

Took the battery out of my 71' Commando to charge overnight, when I replaced it I mistakenly reversed the battery cables. Pop! :shock:
I've replaced the blown inline fuse on the negative battery cable, but still no power to headlights and no spark.
How many things did I mess up with this dumb mistake???
Boyer MkIII installed.

Any and all help appreciated.

No headlights is odd.
Your power wire(s) may have frazzled, so you may be looking for a melted wire - somewhere near the battery.
Or at the back of the switch.

I've seen something similar done to an Onda.
Negative earth lets out just as much smoke.. !

Good Luck.

Or at the back of the switch.

Click to expand...

yep, that is where I found a blackened wire when I reversed the leads as a young lad some 40 years ago

The rectifier, zener diode, the 2 MC capacitor, Boyer Mark III and your spark coils are the only items on your motorcycle that are polarity sensitive. If your ignition switch was off when you hooked up your battery, only your rectifier, 2 MC capacitor, your axillary power plug and your ignition switch will see any electrical potential. The zener diode no doubt is ruined and there is a good chance that your rectifier is ruined as well. The 2 MC Capacitor I doubt was damaged in that short of a time that it took the fuse to blow.

If your master switch happened to be in the on/ignition position, then your Boyer Mark III could have been damaged. Your spark coils would not have been damaged at all.

Your headlights are not at all polarity sensitive, and there is no reason why they would be damaged with the battery inadvertently hooked up wrong. That is about it - I don't know why your headlights do not work. It almost sounds as if you blew another fuse and possibly none of the lights are working. Good luck!

What kind of fuse was it (glass?), and what was it's blow rating ? Somewhere around 17 for a modern type glass fuse is goodly but if you ran higher then things will get damaged. (Rectifier , etc.). Check the fuse contacts in the holder for burning too and clean them. Think of installing a separate fuse in the wire to the Boyer to protect it in the future. Keep tracing.

clayhound said:

How many things did I mess up with this dumb mistake???

Click to expand...

Possible the switch and hopefully just the fuse holder.
What exactly was the fuse that was in there?

Was there smoke? If so, that will also have to be replaced. :lol: Sorry, just an old Lucas joke.

pvisseriii said:

clayhound said:

How many things did I mess up with this dumb mistake???

Click to expand...

Possible the switch and hopefully just the fuse holder.
What exactly was the fuse that was in there?

Was there smoke? If so, that will also have to be replaced.

Click to expand...

Getting more expensive as old supplies are used up. NEW batches are priced at stratospheric levels. :evil: