[C320-list] Mystery

[hcreech at comcast.net]

OK, I need to solicit the aid of those on the list that send out posts regarding electrical problems.  You know who you are, the one's that send out posts that I, and I suspect, very few on the list understands.
Here is my mystery:  coincidental to the replacement of one of my batteries, the circuit breaker that controls the bilge pump tripped when ever the float switch activated.  I could reset the breaker and turn the switch on and the pump would work fine, but again every time the float switch activated in the auto position the breaker would trip again.  I assumed, wrongly, that the float switch itself was the culprit, and I replaced it.  No good, still trips.  Therefore I am at a loss to figure out what is the exact cause.
This is why I need your help, as I said, you know who you are!

Sincerely,
Herb Creech
Cloud Chaser #606