COOLING FAN DOES ONLY TURNS ON WHEN AC IS ON
check the fuse and the compressor relay and check the gas if it enough because if a gas is not enough in some car the compressor will not pick and check if the compressor have not hook.
What car is it? When the A/C is on, the fan (the coolant one) will always start too. If you wired it and it starts, then it works ok. Search for this part on the radiator (I think it is on the left - drivers side, on the inside of the engine bay) and take the wires out. Take some wire/paper clip and join the wires. If the fan starts, this is your problem.
Sorry about that, check this other pic, please.
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