Run269 said:that's a circuit breaker, 30 amps. should ohm out. only way to test it would be to put a load greater than 30 amps and see if it kicks out i guess. maybe your mouse tested it and got the short end of the deal.
i would think that if the ohm meter said there was continuity there it would be good. i've got one too on my firewall, i'll check it tomorrow and we can compare notes. no power to mine yet still in the resto stage.
they were used for power tops and also rear defoggers(i think) and power windows. mine came with my power window harness.