Pulleys

if it is spinning slower, it makes less voltage, so more current is drawn (same power = volt*current) and more current heats up connectors and wire. If you battery gets low, too much current could be drawn through the alternator wire.

The 87-93 5.0 all have the alternator connector/wire fire problem without the pulleys.

They normally replace that alternator (used in other cars too) with a 3rd generation in trucks or cars that idle for long periods, the 3rd generation puts out more current at less RPM so you can have it idle with AC on and it doesn't burn out the wires/alternator.

thanks. Between two primary companies, one said premature failures and the other said no problem.