Well...since the guy never got back to us, I don't know how his story ended.
Good luck Bohemian, I hope ya figure it out.
I think now I'm at the point where I'm getting stupider the older I get so I'm not confident I can help you. Nothing I said seemed to help him either and that was a couple years ago.
I have not had that particular problem myself.
The cables will heat up but they shouldn't be smoking themselves or the battery.
Sure sounds like a short somewhere. Especially if it happens as soon as the cables are connected without even trying to start the bike.
For what it is worth, I'm thinking it's the solenoid that is shorting to ground.

 

Sorry for hijacking an ancient thread… I'm aware it isn't in the 'sportster' section, but I figure my question suit this thread perfectly.

I recently acquired a low mileage (1,700miles) 2013 Forty Eight.
Bike wouldn’t start, strong clicking coming from the solenoid.
When activated manually, sparks fly from the solenoid (but engages and spins).
New battery checked all fuses and cables and ready to put everything back together.
However, I’m having some doubts on the grounds of the solenoid.
I read here its normal to measure no resistance between frame and starter cable due to low resistance of the windings & brushes. However, I doubt if it’s correct I don’t measure any resistance between 2/3/4/5 and frame.Anyone has a chance to check this? I’d be very grateful…

With all cables, connectors, battery, fuses… on bike disconnected
1) Battery positive connection = Not grounded
2) Start switch connection = Grounded (cable not grounded when disconnected)
3 / 4) Start switch cable = grounded
5) Solenoid to starter cable connection = Grounded (not grounded when 5 + 7 disconnected)
6) Solenoid housing = grounded
7) Starter cable = grounded

 

the terminal is loose - a bad ground < no idea how they do that with a new bike but shovel FXR will do that if the under the bike ground is loose - engine to frame

this section is all antiques today not many are even remotely interested in those machines

 

Cool, thanks for the response.
Will give it a go in the tech section.