Hot water heater in Thor ACE 30.1
I found out I didn't have any hot water while plugged into land power. Circuit breaker was off and wouldn't go back on. Removed the hot water heater from the compartment and looked behind it where the wiring is located. I found the relay was corroded, especially where the black hot lead comes in from the breaker. In fact the tab broke off in my hand. Went to an RV store and picked up another relay that looks like it fit and it did. I cleaned up the wiring, soldered a new tab on the hot lead and put the wiring back on the relay; black wire from the heater element, green wire, yellow wire and the power black wire with new tab. Since there was no water in the heater, I emptied it to remove the unit, I wanted to test to see if the heater would get current when the inside switch was turned on. With daughter inside manning the switch and me outside with the meter, I looked for the 120 Volt AC across the heater element when she turned on the switch. Nothing was measured. I looked across the main power lead and there was 120 VAC there.
Question is, how does this relay work? Where does it get the signal from to close the circuit to the heater? Is there anything I am missing to repair the water heater????