Most of these tractor alternators are only 40A…but there are a few optional at 70/90A.
The problem will not be your alternator (if you have an open-station tractor).
The problem will be that an automotive radiator cooling fan is designed to SUCK or Propel air thru a radiator-Shroud…. not push air downward onto You. I believe you will find it to be a mistaken plan, and that you will find only a barely-discernable breeze of Warm air and fan-Noise.
Why do I think that..??
.. Because I removed it and sent it back to the seller after I had that experience myself.
As TGHS pointed out, a portable “truckers fan” can be used to direct a better “blast of air” at your face or whatever, much simpler, cheaper, more effectively. IMO