95 wagon 1.9 (electric problem)

The vehicle drives very well and the a/c is great but...at a stand still the a/c blows warm air.The (under the hood)fuse box had a 40 amp (green fuse cube) that was blown so I replaced that fuse along with the relay in the same area marked cooling fan.Now after a week the 40 amp fuse is blown again (no black mark on glass).I can hook the radiator fan motor directly to battery and it works ,but it doesn't work normally now because of the blown fuse. Would appreciate any help here.Bernie