Without plug in how do you test a ford alternator?

Any Auto Parts store can check the charging system for you. Testing the alternator is simple and basic. You need to check the voltage and amperage output. The voltage is easy enough to check with a voltmeter. If the voltage is between 13.5 and 14.5, engine running, it's a good bet the alternator is good. To check the amperage output, you'll need some special equipment. You'll need an ammeter and a load tester to check the amperage. I would let an Auto Parts store run that check as they have the equipment.