You need a HIGH current source, some relays and a swtich and some wire. By the time you buy all that I suggest you take a serious look at one of these............
Tom Moss
88 GT 5spd Vert 3:73s, Flowmaster catbacks, stock cam +4°, GT40P heads & 1.7 rockers, Jet-Hot coated MAC P headers, 97 Explorer intake, 65mm TB and 19# Explorer injectors. 277RWHP/330RWTQ
One place you can get a good 12v source is piggy backing your alternator wire that runs to the starter solenoid if the fan connection is on the passenger side. If it's on the drivers side I would get your 12v power from the battery and have a switched 12v wire tapped into a wire that gets a constant 12v with the ignition on (such as radio or your ignition switch). This wire can be much smalller (16-18 gauge) to activate the relay.
Make sure you use the appropriate fusing and relays though. Tom probably still has nightmares about my electric fan questions.
Well I have it all done it seems to be working good, it is wired to the solenoid and also through the firewall to the fuse box, it looks real clean, I am happy with the way it came out.
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88 Gt hatch, 96 5.0 motor, GT40 Cast Heads, Explorer upper and lower intake manifold, Lunati 51014 Cam, 3.55 gears, B&M ripper, rebuilt world class t-5, RAM HD clutch, Crane Valve Springs and retainers, FMS 1.6 ratio roller rockers, Eibach lowering springs, BBK 70mm TB and EGR spacer, C&L 73mm maf, BBK long tube headers, BBK short O/R H-pipe.....more to come.
Questions about hooking up my electric fan 
