My 1992 Subaru Loyal 4 door sedan has 2 belts one goes to the alternator. How do you tighten the other one? Belt screeches badly.

SOURCE: alternator belt diagram 1992 Isuzu trooper

1. Remove battery terminals and secure them away from the battery posts using nylon wire ties.

1a. Fine some comfortable eye glasses (clear or yellow) and keep them on. There are plenty of opportunities to get debris in your eyes during this procedure.

2. Spray "PB Blaster" (loosens bolts) on two bolts that secures alternator.

3. Jack-up vehicle on side to access alternator. Use a jackstand to support.

4. Using a 10mm open-ended wrench, loosen the bolt that swings the alternator. Screwing the bolt "in" or toward the engine will allow play to increase in the alternator belt. Loosen the 12mm bolt slightly next to the 10mm bolt (approximately 1.5" toward engine).

5. Continue to loosen 10mm bolt until there is enough slack in the belt to remove the belt from the alternator pulley.

6. Remove belt. It may be possible to remove belt without removing fan faring. Maybe not. If not, you will need to remove plastic fairing. If you must remove fair, go below fan fairing and disassemble connectors that hold together pieces of fan fairing. Carefully remove.

7. Install alternator fan from above.

8. Check that alternator belt is on all tracks (from below with a flashlight), and slowly tighten.

9. Secure 10mm and 12mm bolts. Recheck tightness.

10. Reassemble battery connection and run vehicle at idle for about 5 minutes. Check belt for proper tension.

11. CAREFULLY check tension of belt. Or disassemble battery connections and re-check belt tension.

12. Reassemble fan fairing (if not already assembled), re-connect battery terminals, and have a nice day. :-)

SOURCE: Screeching sound from engine

I can pretty guarantee you it is your altrnator belt.. By turning on your headlights, it creates more load on the alternator, which in turn makes the belt work harder. To confirm, you can try some silicone spray on the belt. The noise should change or disappear. This happens a lot in winter when dirt gets on the belts.
Usually that will solve it. If not, you may have to get the belt changed.
Good luck,

Dan

SOURCE: alternator belt is screeching when i start the car

tighten the belt

SOURCE: how to tighten alternator belt on 83 nissan pickup

loosen the adj bolts and pry the alt to tighten the belt. if you are at the end of the slot, you will need a new belt.

SOURCE: how do I tighten my alternator belt?

did you get the right length belt or correct belt? there should be a bolt to loosen or tighten your belt separate from the alternator.attach bolts..