Blower motor resistor corroding and burning up is commonly due to MOISTURE in the airbox and wet heat cycles being that the vent system does not have a proper filter to atmosphere. Parking under trees dont help! These resistors burn out frequently if your alternator and battery sytem is overcharging aswell. When your blower motor resistor is melted you will probably have a wierd cold start aswell. Most of the time there will be a slow power draw coming from one of the last two pins, sapping your battery night after night and causing issues on coldstart like rpm hunting. Check yaself before ya wreck yaself and never spray bleach into the box either. This is going to make everything inside the box electrical components rust and corrode. Commonly causing your blower motor resistor to melt. Woo jesus chrystler