Why isn't my hot water heater element getting electricity?

The power comes to a very old fusebox/switch with two fuses--both of which are still good. Out of this two wires go to the thermostat and from there to the element. Using a tester, I find that one wire has juice, but the other doesn't. Same thing at the fusebox/switch. It has two sets of contact points (which feed into the wires). One set seems live, the other dead. I already replaced the element, so I don't think that's the problem...