mainly for people who have aftermarket fans or relays are toast etc....

the best way is the most common of tapping into the green/white wire off the f plug of the relay and simply grounding the switch...however my car has been chopped and screwed so many times by electical geniuses that the option wasnt feasable

here is what i did after another member on the board helped me out (Tough87)

go to Walmart
buy a multi-plier made for electrical wire (strips, cuts, clamps all in one)
buy a 30A/12vDC switch (with led if youd like)
buy a atm fuse holder (so you can put in an inline fuse)
atm 30 fuses
12-16 gauge wire
and some assorted connectors

total was about 15-20 bucks

1. (disconnect NEG batt cable)

2. on the back of the alternator there is a screw where the POS battery cable attaches...remove this screw...also insert a 30 ATM FUSE into your ATM FUSE HOLDER

3. Take the wire you selected and attach a ring connector to one side and then connect the other side to your ATM FUSE HOLDER so now youre taking power from the alternator connection and then running it through the fuse holder with your 30 ATM FUSE (NOTE: you will attach the open ring to the alternator screw and reattach the connection to the alternator to gain the power)

4. Run the other side of the FUSE HOLDER wire to the power prong of the switch by using a sleeve connector and more wire (NOW THERE SHOULD BE POWER ALL THE WAY TO THE SWITCH)

5. Now run more wire from the ACC prong of the switch down to the power wire of the fan and connect it together...now you need to take the NEG/other wire from the fan and ground it.

6. Now you should have the fan working and the led light NOT and the ground prong on the switch should be untouched...the reason the led light doesnt come on is bec it needs to be grounded...simply ground the "GROUND" prong of the switch (run a wire with connectors on both sides and connect the wire to the body of the car at a safe place) and the LED light should
come on with the fan

I hope this helps some people...i kinda found it hard to do bc no one would tell me anything except for Tough87 so now i hope others can use this info to do it right the first time...BTW this only takes a matter of 15 minutes if you do it right the first time

 

sounds simple. normally i am not a fan (ha, "fan" get it) of directly switched curcuits without relays, but you fused it and everything. nice job. i have a switch for my secondary fan as well. but i was fortunate enough to have a PO who was not inclined toward hack job wiring.

 

I made my own harness show that works too i have a "backup set" that is ground and power through a 50 amp fuse (running 2-speed fan)

What should be noted is that the stock setup is GROUND SWITCHED. So this wont work with a stock setup. I know you mentioned aftermarket just wanted to get that out there.

 

QUICK BUT EASY SCHEMATIC using color coordination to illustrate setup

KEY incase you forgot
drk red = wire
blue = connector
green = 30 ATM fuse
orange = atm fuse holder
red = switch/switch prongs
black equals = grounds

ALTERNATOR-------------------Power Prong

Fan Power Wire------ACC prong

Fan Ground Wire-----Ground

Ground Prong on Switch-----Ground

K>I>S>S = keep it simple stupid
always the best method
good luck...its as easily put as i could do it