Troubleshooting constant running Aft Bilge pump

[Scarlet Knight]

At the dock the day after having my 2006 Sailfish out I noticed the aft bilge pump was running constantly and would not shut off, no water in bilge. Checked manual helm switch and noticed no matter what position I put in it was lit showing it was on even in off position. I checked float switch and it was not blocked, pump did not go off. Put float switch in down position pump still ran as it is directly wired to batteries. I pulled wires from helm switch and disconnected battery. Reinstalled wires on helm switch, secured float switch back into position, reconnected battery. All seemed fine as bilge pump did not run once battery was reconnected. Came back today and bilge was running again. We did have thunderstorms. My guess is once pump is triggered on it is not gettiing signal to turn off. Is it the float switch? If it is float switch how do you remove aft bilge pump to access float switch wires, it does not have a screw on base nor seem to have easy tabs to push to release. It is the original 1700 GPH pump direct wire to float switch. Can I cut wires to float switch and splice in a replacement? Any troubleshooting ideas?

 

[Scarlet Knight]

One additional piece of info not sure if this is related to this issue. The aft access area smelled like sulfuric acid as I checked out bilge pump. I noticed one of the Deka starting batteries had broken open on top and spilled almost half of its water into the bilge. After cleaning up and washing area down with copious quantaties of water I will need to replace the battery but could the inclusion of the acidic water from the battery have comprimised the float switch or bilge pump casuing the problem of not shutting off?