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, 4X Guard Trans skid, Factory Engine, T-case, Tank skids, Modded BoulderBars sliders, OME 927/948, Bilsteins, JBA A-Arms & 1/4" top plate, 1 extra rear iso/side, Moabs with Firestone Destination AT's 255/70-16