What amount of amps does a 1990 ford ranger 2.9l alternator use?

What amount of amps does a 1990 ford ranger 2.9l alternator use? - 1

Alternators do not USE amps, they produce them for the use of the car's electrical components, which are many, but rarely are they used all at the same time.

Look like your ranger needs an alt w output from 60-80 amps depending on platform options.
http://www.rockauto.com/en/catalog/ford,1990,ranger,2.9l+177cid+v6,1137697,electrical,alternator+/+generator,2412
"How do you determine the size of alternator for a vehicle?"
for a stock platform, I don't bother. Why? Someone else figured that out and cracking the book is not beneath me.

Alternators don't "use" amps… They put out amperage.

They use 1 to 5 HP and put out 5 to 100 amps at 14 volts depending on load
.