How do you do this any one have any pics??

Look above the accelerator pedal and you will see a wiring harness. I think about the forth wire from the bottom is the one. anyway it is a white and green stripe wire. Just tap into this wire and then to a toggle switch to ground.
Don

What Don said , also if you want key on key off operation , at the bottom of your front hood strut , you`ll see the wire loom, and that same green/white wire, you can notch it there , ( don`t cut ) then run a ground wire from that to the bottom of your hood strut bolt 10mm. when you turn the key on the fan will come on --when its turned off--the fan will turn off. I used to forget and leave the toggle on in some of mine when I went into a store or something and come back out and my battery was dead.

When I first got my 87 GT, the kid that owned it before me was having cooling problems. His solution was to hard wire the cooling fan to a toggle switch in the dash. He cut the wires & ran some zip-cord through the sunroof.

One of the first things that I did was repair all of the wiring back to stock. This car should have been able to run in the Arizona desert with no problem. When I got under the car, I discovered that he had been "off-roading" and had crushed his heater core pipes flat and both of his cooling pipes were crushed half shut. Yeah, he probably reduced the capacity of the gas tank by 1/2 gal too LOL.

Anyway, I replaced all of the cooling pipes with good ones from a parts car. Now the car runs as cool as can be.

Anyway, good luck. I suggest if you must do this, tap into the ignition hot wire under the dash so the fan shuts off automatically when you shut the engine off.

From the Fiero online service guide:

Installing a Fan Switch

There has been a lot of discussion about the Coolant fan temperature switch. Your Fiero coolant fan is turned on & off by the inputs from the coolant temperature sensor, speed sensor & the A/C system. Battery voltage is supplied at all times to the coolant fan relay. The fan (or fans incl the rear fans in those so equipped) is energized by merely providing a ground. This is done when you put the A/C in MAX. NORM, or B/L, or the A/C High pressure cut out switch. When the coolant temperature exceeds 235F. The coolant temperature switch closes, and provides the ground to the relay coil to be energized. If you want to switch your coolant fan on whenever you want, all you have to do is manually provide the ground through a switch. Find the main wiring junction block on the front firewall above and forward of the brake pedal (inside the car!) Find the dark green and white stripe wire in plug F9 (4th up from the bottom on the left side) and splice into it through a switch, to ground. (Do not cut the green/white wire). When the switch is turned on, with the ignition on, this will ground the relay, which activates the fan in the same way the coolant temp switch & A/C switch does. I located a black rocker switch in the plate where the defogger switch normally would be, but you can find any good spot. No more worries about creeping temps in hot traffic! The real question is why do this at all? The Fiero was designed to run at these temps, and when it gets hot the fan comes on! (supposed to!). Maybe all you need is a new coolant fan sensor!, especially if the fan(s) come on when you put the A/C on.

From: Paul Vargyas

I tapped into the wire under the dash and ran it to a toggle switch I bought at Radio Shack. It's located below the hatch release where the defogger switch? would be. When the ignition is off, it's off, but I can control when I want it on or off.

Just to clarify things
When the green and white stripe wire is grounded, the fan will not run with the ignition switch off.
So you do not need to worry about leaving the toggle switch on when you turn off the ignition.
Don

Where is the best place to pull a ground from??

quote Originally posted by mmeyer86gt/gtp: Where is the best place to pull a ground from??

Any metal part of the chassis. Crimp a ring terminal on to the end of a piece of wire, drill a pilot hole, scrape off some of the paint around the hole, and fasten the ring terminal to the chassis with a self-tapping screw.

Connect the other end of the wire to your switch.