wanted to know if any of you people could answer a question about a cooling fan. I'm wanting to put an auxilliary cooling fan on a 97 f150, but would like to keep the belt driven fan also. The reason for my doing this is that a friend of mine had a 89 f150 that had the same set up that im going for. His electric fan would come on at a certain temp and then stay on after shutting off the truck to keep the engine cool at its hottest point. It would then shut after it got down to a certain temp. you may have heard others like this while walking by a car in a parking lot. He got 225,000 miles out of this engine when he sold it, and it was still going strong, and i have a good guess this is why. do they sell such a system? could i get a system out of a donor car/truck with all the wiring, timers, and sensor. any input?

 

Your thermostat controls engine temp, if the cooling system is working properly an extra fan will not help. When the engine is shut off the water pump stops circulating coolant thus the extra fan will cool off the radiator only. There is nothing to circulate the coolant thru the engine. The only case when an extra fan may be of value is when idling for long periods of time in extreme heat. When driving at 60+mph the fan actualy slows down air entering the radiator.

 

I have a GTP that does that exact thing. It was programmed that way from Digital Horsepower. But, being that your electric fan isn't factory, it probably would be a royal pain, and I agree with Bubbadewsky, if your water pump isn't circulating then all you would be cooling is the radiator.

 

I have done what your talking about, minus the after running part. However, if manufacturers have electric fans that stay on after shutting down the car(taurus, volvo, practically anything with an electric fan) then there must be some benefit. I ran mine as a supplemental system for my blower. I used a 5.0/4.6 fan from a 95 Mustang GT and wired it myself, but I put it on a user actuated switch instead of a thermostatic switch. It does make for really cold AC at idle in traffic though

 

Electric cooling fans continue to run after engine shutdown because the temp. sensor in the top of the engine says the engine is warm. It stops when the engine cools off only due to the engine being shut down. The fan is a high amp. usage item so the fan is wired to the sensor and a relay to a high amperage wire connected directly to the main hot wire in the wiring harness. If the fan stopped when the engine shut down it would have to be wired through the ignition switch. By by-passing the ignition switch there is one less chance of electrical failure of the fan. Almost the same as when your headlights stay on even after the engine is shut down, until the headlight switch is turned off. (The headlight switch operates like the fan engine temp. sensor, it tells the associated equipment to stop)

 

Unless you have a demenstratable need for extra cooling why bother with the expense and labor to mount one.
A fan of any worthwhile airflow will take very high starting current and still take power from the alternator and battery while driving, causeing higher fuel consumption and use on the charging system.
Running a fan after engine shuts down will cool the system a bit quicker as the thermostat is still open and slowly closes as the coolant "still' circulates by normal temperature difference until the flow is vertually stopped by the thermostat closing.
I run an manual control electric fan on a dirt track sprinter with no thermostat and the fan will still cool the 'engine' much faster while the fan is running with the engine off because there is nothing to stop the normal coolant circulation from temp. difference between the radiator and the engine block..
If your trying to relate engine life to the extra cooling, there is no proof that this has ever had such an effect. The coolant system is a closed system that needs to carry 1/3 of the heat of combustion way with the other 2/3 being lost thru the exhaust/ convection/radiation and conversion to work at the crank.
Cool down has no effect on engine life providing there is no fault that causes overheating or some other problem..

 

I just flushed my cooling system this Friday. My truck just went over 150,000 miles and has never run hot. To flush the cooling system you gotta get that thermostat to open to get to the block and heater core. I was thinking I had a 195 thermostat and the truck wouldn't go above 188 degrees when I threw my OBD11 computer on it. It was a record 90 degrees last Friday and I still had to stuff quilts around the grill and below it to help stop the air flow. Then I had to rev the engine up to 3000 rpm to get that thermostat to open. I could only get that engine up to 203 degrees. You shouldn't have a cooling problem. Too cool of an engine is bad. You need hot oil to remove the contaniments in your engine.

 

thanks for the replys. about the engine not circulating coolant after you shut off the engine, is not true. For proof look at a 1953 farmall super A tractor (if you can find one), it has no water pump and is liquid cooled. When the engine gets to a certain temp the coolant starts to flow on its own. you boys must not have grew up on a farm. in any case this system i spoke of on the 89 f150 was stock and was built that way for a reason, so the engine must be getting cooler with the fan running after you shut the engine off. therefore you don't have any heat damage to an engine that is already hot on a 100 degree day or pulling a heavy load.

 

Before you waste money on an extra fan look up the 100,000 mile thread and see for yourself. You do not need the extra fan to get high milage out of your engine. But if you are still set on using an extra fan you will have to mount it as a pusher. That involves making the fan turn opposite to its intended direction. Make sure you follow the manufacturers procedures for reversing the direction. In some instances it involves turning the fan blade around. if you want it to run after the engine shuts down you will need a temperature probe type controller to shut it down at your desired setting. There are two ways of doing it. One is to probe the rad and the other is to probe the coolant. Wiring the controller is not difficult just follow the instructions but use a power wire that is hot all the time. Pulling off the positive battery terminal is an option. Now for kits you could contact Mike Troyer he sells a kit. It is a duel kit but if you only want one fan he might be able to split one in half. Here is his contact info.
Mike Troyer
Troyer Performance/Performance Products, Inc.
Truck & SUV Performance Specialists
Supercharging & Custom Tuning Experts - America's Oldest Superchips Distributor & 1st Superchips Custom Tuning Dealer
Web Site: TroyerPerformance.com
(540) 862-9515
Email: Sales@TroyerPerformance.com
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Looks like any amount of advice will not change your mind---have fun. By the way I did not grow up on a farm as a result I can't pluck chickens either but I do understand thermo-dynamics and when that thermostat closes there is no circulation. All hot coolant will rise in a closed system be it in the engine or radiator, there is nothing that will cause the coolant to flow into the radiator where you are cooling the water with the elect. fan once the thermostat closes.

Our trucks have plenty or areas where improvements can be made this is not one of them