If the combustible gas emitted by the melting plastic does not disperse due to air flow through the engine compartment, it could ignite and in turn ignite the fan guide in the alternator.
Electrical System — Alternator/Generator/Regulator
On certain passenger vehicles, one of the diodes used in the alternator may have been damaged when built. This can eventually result in failure of the diode and an electrical short which could melt the plastic housing.
Dealers will replace the alternator. Owner notification began July 29, 2002. Owners who take their vehicles to an authorized dealer on an agreed upon service date and do not receive the free remedy within a reasonable time should contact Nissan at 1-800-647-7261 or infiniti at 1-800-662-6200.