AlfaCentro: Feature Articles : 105 Electric Fan Conversion

Re-Fitting the Radiator
Now that we are sure that the probe will reach the radiator from the mounted control unit, it is time to replace the radiator. Make sure the U-shaped rubber pad is on the bottom of the radiator and place it into is cradle. Bring the 2 wires from the fan motor over the top of the radiator and out towards the control unit. Lean the top of the radiator forward and attach the thermal probe into the fins. A kit is provided to hold the probe in place. It is the same type of rod and locking disk set-up used to on the fan. With the probe in place and clear of the fan blades, replace the rubber spacers and washers and screw in the 13mm bolts. Re-attach the water hoses and tighten the hose clamps.

Wiring the Fan
Now that everything is mounted it is time to do the wiring. There are many wires coming out of the control unit, but a few of them are not used. There is a blue wire for a second fan and a green one for the AC clutch. As my car has no AC both these wires were of no use and can be just cut short. (One could use the blue wire to mount a °fan on° indicator light inside the car to signal when the fan is operating.) There are 2 wires that need to be grounded, one from the control unit and the one from the electric fan motor. I soldered these two together and into a connector then grounded them to an already existing ground screw in the engine compartment. You might want to place male/female plugs in the 2 wires from the motor so that next time the radiator comes out you can simply unplug those leads.

There are 2 ways to wire up the fan. It can be made to only run with the ignition switch on or it can be made to continue to run after the motor is shut off. The coolant and engine are still hot after shutting down, so many feel it is best to let the fan continue to run. If you wish to let the fan run after the engine is shut off, there is a yellow wire that should be tied together with the red wire. (A mechanic friend cautioned that he has seen many cars drain their battery in the summer because their fans continuing to run on. My Milano has been wired to run on for 3 years now without any trouble, so I chose to let it run on.) If you choose to have the fan shut off as the ignition key is turned off, then the yellow wire must be connected to a source of switched +12V. I soldered the red and yellow wires together and attached a connector. I chose to connect them to the + junction at the alternator. NOT the output from the alternator, use the junction where the hot lead comes from the starter motor. On my car, this lead comes from the battery in the trunk, to the starter motor, then over to the alternator. So, now we have our grounds connected and our hot leads connected, we need to connect the positive lead from the fan motor to the orange ( switched lead ) fused wire from the controller. That's it for the wiring. These instructions are all covered in the control unit instructions.

Time to refill the radiator with coolant. Make sure the heater valve inside the car is open in the °hot° position, and that you fully bleed the system of any air via the plug provided directly behind the thermostat.

RECONNECT THE POSITIVE TERMINAL TO THE BATTERY.

The instructions with the controller tell you to start the engine and place your hand on the water hose leading from the thermostat to the radiator. As soon as you feel the thermostat open, that is when the fan should come on. You adjust the rheostat with a small bladed screwdriver turning to make the fan turn on at a higher or lower temperature. I found this to be more difficult than described because the hose only gradually got hot, not suddenly. So, I used my temperature gauge in the car to help determine when to turn the fan on. The control unit comes factory set to turn the fan on at 160 degrees, my setting seems slightly higher than this between 170-180.

I took the car out for the test drive and all seemed fine. The fan continued to cool for about 2 minutes after I returned. After driving, be sure to check your coolant level and top it off if necessary

Follow Up
To follow up on the exploding fan story.... Yes, the fan was only 2.5 years old and had only 14K non racing miles on it. But, we discovered why it probably blew.

Several digesti had mentioned motor mounts, but the mounts were only 2.5 years old also and they looked good. Ben Higgins had mentioned that if you cannot get one of your fingers between the crankshaft pulley and the sway bar, something was not right. After installing the electric fan, I tried his finger test and I couldn't do it, the crank pulley was indeed too close to the sway bar for my finger to pass through. With a flashlight, I carefully checked the mounts, they still looked good and non bulgy, but lo and behold, all 3 nuts were gone off the engine studs, on the driver's side, that secure the top of the mount to the engine ! All 3 nuts were either not installed or had backed off !

So, with a jack and wood under the oil pan, we lifted the engine a bit to take the tension off the mount, and installed lockwashers and 3 new nuts. Now, I have that finger's worth of clearance and my engine is sitting much more level. I also picked up a bit more clearance between the oil pan and the road. This is another simple thing to check for when you do a once over on your engine. Do that finger test!