Two or three... four if you count the tensioner. I have not decided yet if I will leave the span between the alternator and PS pump as is.
The tensioner pulls the belt up between the crank and the AC. Then the idler between the AC and alternator. Then the second idler between the PS pump and the crank. Result is more than 180 degree wrap on the AC, alternator, and PS pump. Wrap around on the crank pulley wont be quite 180.
