Do the 2004 jeep with 4.0 straight 6 have a clutch fan on water pump?
No, the 2004 Jeep Wrangler (and other Jeep models) with the 4.0L straight-6 engine do not have a clutch fan on the water pump. They use a viscous fan. While both types of fans are designed to control engine cooling, a viscous fan uses a fluid coupling to adjust its speed based on engine temperature, whereas a clutch fan has an on/off mechanism.