pull the plug off the rad thermoswitch, bridge the pins. if fan runs the switch is to blame, or the rad is blocked so coolant isnt getting to the switch. if it doesn't run either the fan is bust, the wiring is faulty or the fuse has blown. jump the fan direct to the battery, if it runs you know its the fuse or the wiring. if fuse is ok look at the 2 pin plug near the rad, its probably just a dirty connection here. the plug isnt waterproof which isnt ideal.
with the loom fault, does the battery light come on with the ignition then go out? if not, the blue wire from alternator is the problem, or the dash bulb is blown. if it does, id say battery is toast