The resistor in the low pass circuit fried.

It sounds like the subwoofer cabinet has a built-in low-pass crossover circuit in line to protect the drivers from high frequencies. My hunch is that the resistor fried. Put an ohmmeter on each side of the resistor and measure its impedance. I’ll bet it is infinite.

If you have an external active crossover that is only feeding bass, then this superfluous. I would just remove the resister and capacitor and run a new internal wire directly from the quick connect block to the drivers.

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