To my knowledge, every 22R or 22RE that I have ever seen doesnt have an idler pulley to adjust tension on the alternator. They are only used on the power steering pump.
If the belt feels loose then it is likely causing the problem. When you said you had new belts I assumed that you installed them. If you havent ever tightened a belt then you might want to buy a Haynes (preferably) or Chiltons manual. They cover the basics such as belts and might be a good learning place to start. To adjust the tension on the alternator simply loosen the nut on the alt pivot bolt on the back bottom of the alternator and locking bolt on the bracket on the front of the alternator. Once its loose put a pry bar between the block and alternator and pull down to put pressure on the alt. At the same time tighten the lower nut enough so it wont move back easily. Remove pry bar and put hand pressure on alt and fully tighten the front bolt. Then finish tightening the rear nut. There should be about 1/2" deflection when tou push down the belt between the alt pulley and the fan pulley. This is all spelled out in Haynes or Chiltons. If you still cant do this then I would pay someone to do it. The longer you wait the more glazed your belt will get from slippage.