Elecfandoes notworkwillnotcoolengine elec fan for rad. will not come on so car gets hot

First, test the fan for operation by disconnecting it at the closest plug to the fan itself, then using a couple of loose wires as jumpers, connect the fan to a remote power source like a battery charger or another battery thats got power..it the fan works its good, if not, replace it, if it works then you need to check other things from your ac fuses to all the connections from the ac compressor, all the way to messing with the heater controls..usually if the main control is set to defrost, the override for the fan relay will kick in..mine does.. the fan relay is ocated up on the drivers side fender well in a cluster of 3 -4 relays that look identical but are internally wired different..also be sure the engines temperature sensor(s) are good,,one of these may be a multi wired unit for the fan specifically,,some models vary in the same year...check all connections as road dirt and debris does enter the engine compartment from below, look for corrosion and broken wires..in an emergency like on the hiway, usually the airflow is good enough to keep the car within operating temps..good luck..