If you're referring to the 4.0 I-6, there is an idler pulley located directly under the air conditioning compressor pulley. However, tension is adjusted through the power steering pump. You will have...
The tensioner pulley is off course located in line with all the other pulleys on the front of your engine block and will be the only pulley that isn't connected to another device such as your air...
There is no tensioner pully. The Power Steering pump has a moving bracket that adjusts the belt tension. It has a long adjustment bolt. You have to remove the air cleaner and housing to reach it...
The question you ask is too
involved for a proper answer.
You need to go to a car
parts store, and get a
repair manual for your car.
They cost about $16.00
Or, go to a Public Library.