This Video shows you how to fix squeaky belts on a Subaru car. Usually when the belts start squeaking and screeching on a Subaru car, it is because the belt is too loose. You need to tighten up the accessory belts on your Subaru car to stop them from squeaking. If you are doing this, it may be a good idea to replace the belt altogether, but if you just want to tighten up the belts to stop them from squeaking, this video shows you how to do it. Just remove the belt covers, and then use the Subaru drive belt tensioner’s to put more tension on the belts until they Each have a quarter inch of play between the pulleys when you put pressure on them. It is easy to fix squeaky belt on the Subaru car if you know how to do it. Watch this video to learn how.

Here's where you can get a Subaru repair manual:
https://amzn.to/3iRs86f