All the gauges on my dash stopped working including the odometer. What could be the cause

Dozens of possible causes - fuses, wiring, connectors, modules, etc. Someone will have to do some testing.

Take off the drivers front tire (better yet pull off the bumper cover)and check wiring forward of the tire under the splash shield.The wiring you are to check runs from the module mounted there to the fuse box in the engine compartment on the drivers side. Remove some of the wiring protection close to the module and pull the wiring lengthwise (try to make each wire longer by pulling each individual wire ) You are looking for a wire with a break in it.You will find a broken wire.Repair the break and other semi almost broken wires you may find and your gauges and dash should be back on.I have fixed at least 25 Caravans with the broken wires at this location for this exact problem and other problems.Good luck with your repair.