it should be one of those with 2 prong plug sitting on top next to valve cover.
U can try using a paper clip to short the two terminal together to see if the fan comes on.

Usually there is a 2 prong connector near right inner fender ( as standing infront of car) u can trace the wire to the fan, unplug her and run 12Volt see if the fan comes on. Good idea to fuse your power wire, atleast if it shorts it wont produce a big spark. 20 amp may do or resettable type so u wont blow one.
Is polarity sensitive, or wil reverse the fan LOL.

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