My boat is only three years old..H36. I added a second pump/float switch this weekend only to find out the wire on the original float switch corroted making it useless. If I had a leak...the boat would have been under water. I check my pump with the bypass switch, and check to see the float switch is clean...didn't occur to lift the switch at the same time to see if it works. My bilge is usually dry and so the system has not been tested for a long time. The corrosion on the wire to the switch was barely visible.I will be a little more careful next time in checking things out.abe