I'm not terribly familiar with the CRD but based on your description and the dealer's diagnosis something is backwards...
You indicate the mechanical fan was spinning but the electric fan was not. The dealer says the fan clutch (which starts/stops the mech fan) is bad, which has nothing to do with the electric fan.
"Suggest" to them that you want the tech to do a diagnostic on the electric fan to insure it is operating properly. One other thing that is an issue with the gasser: Make sure the thermostat is installed in the proper direction. It is common for the gasser thermostat to be installed backwards; when installed this way it closes when the coolant gets hotter. Maybe an issue with your CRD...?
My 2 cents.
2003 Renegade, Black
- 3.7L, 42RLE, 4.10's, ARB Bull Bar, Smittybilt XRC 9500lb Winch, 4X Guard Trans skid, Skid Row Engine skid, Factory T-case & Tank skids, Custom BoulderBars, JBA Front Coilovers, OME 948 rear springs, Bilstein rear shocks, JBA A-Arms, Moabs with Goodyear Duratracs 265/70-16