Adding electric puller/pusher fan to antique automobile

[Vetteman61]

Hello everyone,

I greatly appreciate your help ahead of time. I have a 1971 Pontiac station wagon. It has a mechanical cooling fan on it now which is of course attached to the engine. I want to add electric fans to 1) help get a couple extra mpg 2) cure an overheating problem when the air conditioning is on. I have found online that you can get a million ways to do something from automotive forums, but they often aren't the "right" way to do things. I like to do things the best and most correct way and unfortunately wiring things to activate under particular circumstances is something I don't understand, but would like to learn.

I need to have two fans, one behind the radiator/condenser to pull air through the radiator/condenser. This fan should come on like any other automotive fan, when a certain, preset temperature is reached. Another fan will be in front of the radiator/condenser to push air through at all times any time the air conditioner is on.

Here is a picture of the general physical setup just to help with visualizing what I have described

Thank you,
Brandon

 

[alec_t]

Welcome to ETO!

I want to add electric fans to 1) help get a couple extra mpg

Adding a fan (as distinct from replacing the original fan) will result in a reduction in mpg, since the engine has to work harder to drive the alternator to power the fan.

 

[Diver300]

Taking the mechanically driven fan off will improve the fuel consumption slightly. An electric fan that can be switched off uses less power in a lot of conditions.

I don't see why you would have two fans like that. A fan in either position will drive air through both the condenser and the radiator. You could have just one fan that comes on when the engine reaches a certain temperature, or the air con is on. You could leave the fan off above a certain speed even with the air con on, as the car moving will drive enough air through the condenser if you are going fast enough.

 

[shortbus=]

Most of the aftermarket electric radiator fans can be used as a 'pusher' but they a not as effective in that way of being used. The blades are usually optimized for 'puller' use. When mounted as a 'pusher' they obstruct air flow when not "on". To get the most air flow with the fan you still need a shroud to pull air from the whole radiator core. Like this one from Flex-a-lite.
https://www.flex-a-lite.com/electric-fans/12-inch-lo-profile-s-blade-electric-fan.html