When you're saying the pins are crapping out I assume you mean you're seeing overheating/melting around the pins?
Did you replace the connector on the wiring harness after the first failure? There is a splice kit to do this repair and is highly recommended (arguably necessary) when you've had a resistor pack fail--even if damage to the connector isn't obvious. Oxidation, melted plastic, displaced terminals etc. within the connector itself can all cause failures of the new resistor pack.
The other possibility is worn out motor bearings causing it to draw excessive current.
I'd say it was a fan drawing too much current as well, either by worn bearings or internal shorts on the windings that reduce the effective length of wire internal to the motor, thus lowering the resistance and raising the current draw.