I just purchased an '03 auto. It seems that the fan clutch locks up every time the engine comes down to an idle. Most of the time it stays locked through the 3rd shift at least. I had a '03 6 speed and it seems it never locked up unless towing heavy and the water temp got a little warm. I swung by the dealership and of course it is not covered under my remaining Cummins warranty. Any advise, or is this normal? Thanks