Rotary Resurrection - Tech Section

First I should say that there are probably very few efans out there that cool as well, or better, than the stocker. The stock fan is automatic adjusting, and is almost bulletproof. The stock shroud covers 100% of the radiator, whereas most e-fans will not. The main reason to remove the stock fan is if it is defective, or to make more room in the engine bay. It isn’t much of a performance gain, nor is it more efficient, in most cases.

When installing an electric fan on a 1 or 2gen, I use junkyard fans from 91-96 Ford Escorts. These are cheap, plentiful, long lasting, and move a lot of air (as much or more as the stocker) without taxing a stock charging system too much. The good thing about these is that they fit the stock FB and FC radiator well, and they are shrouded to cover most of the surface area, thus cooling the whole area, not just the center like a cheap autozone or summit fan. Others have used ford taurus and pontiac fiero fans to name a few, but these are somewhat more obscure. This writeup focuses on the installation of the escort fan, but can be used for just about any e-fan. Most of the escort fans are 2/3 speed, some are only single speed. For the 2 speed fans I use the lowest setting which moves plenty of air but draws little current. I set my fans up to run anytime the key is in the ON position, without a thermoswitch. Again, **in my experience**, with a healthy stock charging system, you will experience no charging problems with the fan running constantly. Adding a thermoswitch is possible, but I personally don't like them because of inaccuracy, as well as the fact that this just adds another link to the circuit that can fail later causing major problems. IF you wish to add a thermoswitch, do so in the 12vdc+ trigger wire.

Securing the fan to the radiator is pretty straightforward...I use large zipties to the sides of the radiator frame for this. You may have to trim a piece of plastic from the top edge, and drill a hole on the passenger side of the fan...I use the holes where the stock shroud used to bolt to for my zipties. Two ties hold the fan very well, but you can go further if you feel the need.

Find the power wires for the will be a ground (black) and the other(s) power leads. The orange is usually low speed (the one we'll be using) and the yellow high speed. Wire colors vary by year. If in doubt, ground the black wire and run a test wire from the battery + terminal to each of these power wires to find out which is high and which is low...note and use the low wire. Strip insulation off of the ground and low power wire.
I use a standard automotive 12v 4 prong relay for this application. You can use a spare stock relay from a partscar (shown here) or an aftermarket replacement available at auto parts stores such as headlight or foglight relay. These have 4 prongs parallel to each other. On the side is a circuit diagram. When looking at the prongs with the "tab" facing up, the right 2 prongs represent the trigger side (one gets grounded, one gets 12v+, and this switches the other half of the relay on) and the 2 on the left represent the load side. What a relay allows you to do is use a low amperage trigger wire (say from a switch, computer, etc. that should not carry much current) to operate an accessory that requires a large current flow. The load side gets connected to the battery or fusebox (a high amperage supply source) and the accessory + lead that you are powering. When the trigger side makes a circuit (you flip your switch or whatever) the load side connects the accessory to it's high amp power supply and it runs.
You're going to need some decent wire (I use all black so it doesnt stand out in the engine bay), something about 16-14 gauge. And several connectors, so buy a variety pack. Cut all the wires and install the connectors first to avoid confusion. These instructions are mainly for 2gen cars, but can be easily adapted to 1gens. Here are the wires you'll make:

-16" length with 1 female spade terminal and one female butt connector
-12" length with 1 female spade terminal and one male spade terminal
-32" length with 1 ring terminal and 1 female spade connector

The following 2 wires will be joined together by a single large ring terminal (10-12 gauge connector):

-16" length with one female butt connector on one end, the other inserted into the large ring terminal

-8" length with one female spade terminal on one end, the other inserted into the large ring terminal

Now crimp the ring terminal.
Locate the green 6 prong connector by the leading coil. This will supply our trigger side 12v+, which is an ignition lead from the ecu. Find the TAB on one side. In the terminal adjacent to that tab, insert the male end of the shortest single wire. The other end goes to the relay, with the TAB on top, this wire goes to either of the right 2 terminals on the relay.
Find your fan's power supply wire. Use the 16" wire here. INsert the power wire into the bullet connector and crimp firmly, and plug the other end into one of the LEFT hand terminals on the relay. Either one.
Now get your 2 wires joined into 1. Pick a good grounding spot, I use one of the headlight bolts. Put the large ring terminal on this ground and tighten well. Now run the shorter of the 2 wires and plug it into the relay, on the RIGHT side remaining terminal.
With the other end, connect this butt connector to your fan ground wire securely.
With the remaining wire, tap into the main fusebox in the engine bay. Remove the 10mm nut closest the fender, and loosen the opposing one. Pull the box toward the front of the car, and open the door on the side. Loosen the 10mm bolt, **being cautious not to let your tools touch the chassis**. Slide the ring terminal under the bolt with the other ring terminal, and tighten it back down, Close the door, and reinstall the fusebox. The good thing about drawing power here is that you are pulling power from the other side of the 80A main fuse...if there is ever a problem with the circuit it will likely blow this fuse, which will also kill the car. This is a good way to prevent overheating from your fan not working. Of course, if the fan motor itself dies, the fuse will not blow and your car will still overheat. IF you don't want to use the 80A main fuse, you can install a fuse of your own elsewhere in this block and tap in there.
Carefully connect the other end of this wire (remember it is now LIVE) to the remaining LEFT hand terminal on the relay. Tuck the relay and the wires down under the battery out of sight. The engine bay looks stock. Test your fan by switching your key ON. IT should run, and should blow air toward the engine. IT should never run when the key is off.
Rotary Resurrection - Tech Section
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