There should be a sticker on the top of the fan shroud showing a picture of both air conditioned and non-air conditioned routing.
There should be a sticker on the fan shroud or on the bottom side of the hood. If your sticker is missing, that is the same truck I drive. I could post the routing sticker somehow.
Open the hood and there will be a sticker by the radiator (right above the grill) showing belt routing.
The alternator is driven by the drive belt. Find the belt and follow the routing and you will find the alternator.
There should me a diagram under the hood somewhere of how to route belt
The A/C compressor is driven by a belt. Follow the routing of the belt and you will find the compressor.
The belt on a 2000 Ram uses a spring loaded tensioner pulley. It self tightens.
Most vehicles have a factory sticker under the hood showing this. If not, try checking the owner's manual, or contact a dealer service department. They should be able to provide a photo copy of this...usually for free.
The belt has an automatic spring tensioner and can not be "tightened".
Pulley.
In a 1990 Dodge Ram 50 pickup both the 2.4 litre four cylinder engine and the 3.0 litre V6 engine uses a timing BELT
The belt diagram is usually located on a sticker on the fan shroud under the hood.
To change the fan belt pulley on a 1996 Dodge Ram 1500 with a 318 engine, first disconnect the negative battery cable for safety. Next, remove the serpentine belt by releasing the tension from the serpentine belt tensioner. Once the belt is off, unbolt the fan belt pulley from the water pump or alternator, depending on which pulley you are replacing, and replace it with the new one. Finally, reattach the serpentine belt and reconnect the battery cable.