That is pretty cheap if they are any good genos has relays for the gen one for 17.95 . But if the heater is cycling and shutting off the relays are working
If you showed no continuity to ground at the hot side of the heaters then the heater grids are either missing or burned out. bgI did a check on the power side of the grid heater and no continuity meter reads ol there is continuity on the ground terminals. So I checked the terminals on the 92 which I know the heater works and there is continuity on the power terminals