the temp sender is in the head just to left of the thermostat housing and the switch that controls the fan opertation is just under the thermostat housing and to see if the switch is at fault pull it off and place a piece of wire in the bit you've pulled of and the fan should come on, if not check fuse isn't blown and lastly if you know how and have got a multi meter check you've got a live to fan if so could be fan motor that has gone