Afternoon, guys


So my mechanical fan is no longer keeping up in the summer. It gets a bit warmer than I would like idling in traffic and the temps really go up after the engine shuts off.


While looking for a fan shroud I discovered that for the same price as a repop shroud, I could get a dual 12" fan and aluminum shroud setup.


My thought was to run one fan to the key on ignition and have the second on a toggle switch on the dash. When its warm I can flip on the second fan, or when I shut the truck off I can run one fan to keep things cool.


Is this idea sound or riddled with problems?


Also, is a 3G alternator required to keep up with the electrical load?

 

The basic idea is sound, however, riddled with holes on closer inspection lol.

To clarify, having the fan simply run to a switch will draw too many amps and likely burn something. You need to run it to a relay, then the switch. You can also interrupt it with a toggle if you so desire, I do, for water crossings.

A Harden controller is pretty affordable however, and I've used a VW Rabbit controller on my Mustang

 

Having a fan on at all time will quickly kill the battery - even with a 130 amp 3G . Run it off a screw-in temp sensor. The probe-type thermo sensors are hokey and to me, unreliable.
There are links in the tech info compilation. BMW sensors, Volvo relays, etc.... Or step up to an aftermarket controller - even pulse-width modulated.
A 90-amp alternator would be a minimum IMO.
Yes, high-amp relays and even a continuous duty solenoid (activated by a relay signal) is the way to go.

 

I have a lincoln 2 speed fan with a Volvo dual relay switch with low on key power and high comes on with the AC and it works great so far in Phoenix AZ. I tried the thermostat switch n the intake and it became unreliable so that's why it key power now. I also have a champion aluminum radiator, 3g and drive it daily.

 

Being a long time Mustang enthusiast, I've discovered that the late model Ford Contour/Mercury Mystique dual fan assembly is one of the best fully integrated units you can find. I mounted it on my '79 Bronco's OE style aluminum radiator, and in conjunction with one heat range cooler plug, a thermoswitch for 1 fan and computer control for the other, the system overcools in the desert heat of Arizona (cycles on and off). Also, I recently reinstated the A/C in my '79 Ford. Using R-134a requires a higher efficiency condenser and better airflow. The Contour fan assembly affords all of this and my A/C is ice cold.

Whatever route you take with the fans, I would suggest not using fuses for circuit protection, but a circuit breaker instead.

 

I'd just add... warming up after heat soak is typical for an iron head V8... not a problem as long as it cools off after running a bit.

Also... if your cooling system was keeping up before and now is not it could be a weak radiator or fan clutch (if equipped) problem. Electric fans won't fix a weak radiator. Fan clutch is a lot cheaper than an electric fan + high output alternator + wiring/sensors.

 

Or weak water pump, clogged jackets, etc etc. I thought this earlier myself.

 

How would I go about testing the water pump or weak rad? I don't remember really well but it didn't seem to struggle last summer.


Thanks for all of the input guys! This is the exact reason I post.


Should I do the electric fans, I think I will buy the aluminum one. I have read about late model fan swaps, and I hear they do wonders. But I just think that an aluminum sheet shroud would look better.

 

I can't argue with the looks, but these late model fully integrated shroud with fan(s) assemblies are extremely efficient and also very compact. Normally engineered to work in extremely tight spaces and the twin Contour fan setup pulls something like 6000 cfm at full tilt. It also makes a horrendous amount of noise, but cooling is the priority and that it does well. At $100 per assembly (new), it's a very good value.





Dual Contour fans mounted to OEM style radiator in '79 Ford Bronco.

 

I don't know of any way to test for those things, without dismantling things and looking.


You can however, very easily and fairly cheaply replace your cap and see if that helps.

 

According to a CarCraft article a couple of years ago, the is no industry standard for rating fan CFMs so take any rating claims with a grain of salt.

 

What does one put in place of the fan?


this is the fan setup I am looking at
http://www.ebay.com/itm/NEW-ALL-ALUMINUM-RADIATOR-FAN-SHROUD-W-12-FANS-FORD-TRUCK-1966-1979-/281682579959?fits=Year%3A1979%7CModel%3AF-150&hash=item41959711f7&vxp=mtr

 

You just use the stock water pump pulley bolts to fasten the pulley to the pump. Check clearance behind the pulley to make sure there's no interference and if there is, space it out using washers or find shorter bolts.

 

2x.. if currently using a fan spacer, definitely gonna need shorter bolts (with split washers)... Go with stainless steel for that extra **bling**.


I'm surprised that the shroud above is solid... better ones, in my opinion, will have rubber flaps to bleed off air at speed so the fans don't freewheel and prematurely wear out the bearings. Your call.

 

This is a good point and a valid one when the vehicle is driving at highway speeds where the ambient airflow will hopefully be enough to turn the fans off.