I have a 1999 Electra Glide and the negative battery connection melted the lead connection block on the battery. Where are the locations where the cable is grounded out? If there is a loose or corroded connection - could this cause the arcing at the battery connection?

 

How old is that battery? Lead melts at 327.5 degrees F, so it's not inconceivable that your head/engine temps are creeping into the battery compartment and contributing to the melting of the battery posts. Not likely, but as they say, anything is possible.

Remember that electrical resistance creates heat. So if the connection between your negative ground post on the battery and the negative cable was loose and/or dirty, then you introduced resistance and heat. That's the most likely suspect in this case.

Clean all cable to ground/frame connections and your battery post clamps. Get a new battery.

 

Yes, a loose terminal can cause it to arc. I learned the hard way earlier this year. I replaced my original HD battery with a new Deka. I reused the bolts that hold the terminals down. After riding a few times, I melted the posts on the battery because the bolts came loose. I replaced the ruined Deka with another HD battery, used the hardware that came with the new battery and used lock washers. I have been riding months now without an issue and the terminals are as tight as day one. I know better not to reuse hardware if new hadware comes with the replacement but must of had a brain fart that day. Expensive and hard lesson learned.

 

The only way the battery terminal could have "melted" is if the connecton was loose on the battery!