You changed the water pump in your 2001 jeep grand Cherokee but now the air conditioning does not work?

Answer 1

The first thing that comes to mind is whether when you replaced the water pump you purchased a belt that is of the right size to accomodate the pulley that runs your AC compressor. Although I'd doubt that any Grand was ever purchased or even produced without AC I guess its possible which would mean that there would be two sizes of belts available. Check that first. Its possible that the new belt (if you did in fact replace the belt with the new water pump) is slipping on the AC compressor pulley due to a problem with belt tensioning or a defective compressor. With the engine running this would be easy to see and typically be making a squeeling noise. If the AC compressor pulley is turning then a further look at your air conditioning system would be your next step and would make me wonder if your AC was in fact working prior to the water pump replacement.