Cooling Fans

[pontiacgp]

this one is the pusher, I have used that fan as a puller with no other fans and car never overheated. I use it as a pusher now cause it's a bit dangerous to have in an open area...

HD Electric Fan 16"x3 3/4" 2950 CFM

16" Electric Fan Mounting Area Req’d. 16" x 16" x 3 3/4" RPM 1800, AMP Draw 11.0, 2950 CFM

shop.perma-cool.com

this is the puller....

Automotive Electric Fan 16"x2 1/4"2350 CFM

Mounting Area Req’d. 17" x 16" x 3 1/4" RPM 1450, AMP Draw 11.0, 2350 CFM

shop.perma-cool.com

 

[565bbchevy]

this one is the pusher, I have used that fan as a puller with no other fans and car never overheated. I use it as a pusher now cause it's a bit dangerous to have in an open area...

HD Electric Fan 16"x3 3/4" 2950 CFM

16" Electric Fan Mounting Area Req’d. 16" x 16" x 3 3/4" RPM 1800, AMP Draw 11.0, 2950 CFM

shop.perma-cool.com

this is the puller....

Automotive Electric Fan 16"x2 1/4"2350 CFM

Mounting Area Req’d. 17" x 16" x 3 1/4" RPM 1450, AMP Draw 11.0, 2350 CFM

shop.perma-cool.com

I have either the bottom one or something similar as a pusher and I almost bought the top one as a puller many years ago when it came out but I was on more of a budget back then.

 

[jlcustomz]

Better to pull than push & no shroud over the entire radiator surface does not cool the entire radiator. Never had luck with single strap on unshrouded fans years ago. Wouldn't cool stock 350 olds in wife's cutlass around town.
Add on pushers are ok as an auxiliary fan.

 

[roger1]

Here's the 3 relays for my 2-speed dual fan setup. These are Hella weather sealed relays and I use uninsulated connectors which I crimp, solder and cover with adhesive lined heat shrink tubing.

Here is a wiring diagram that I drew up from a schematic in a GM service manual.

The wires labeled L and H connect to my Dakota Digital PAC-2750 controller which is mounted behind my instrument panel:

I also have dual fans in both my '55 Bel Air and '57 Chevy pickup. Also running the 3-relay setup with a PAC-2750 Dakota controller in those.

 

[pontiacgp]

Better to pull than push & no shroud over the entire radiator surface does not cool the entire radiator. Never had luck with single strap on unshrouded fans years ago. Wouldn't cool stock 350 olds in wife's cutlass around town.
Add on pushers are ok as an auxiliary fan.

here is what Griffen says about shrouds....I which they would have answered what a shroud does at above 15 mph cause above that speed cause the shroud blocks the airflow

Why should I use a fan shroud?

Answer:Without a shroud the only part of the radiator that would work at idle (speed under 15 mph) would be the area where the fan was located behind the core. The shroud guarantees that air is pulled through the complete core, resulting in optimum performance.

 

[tc1959]

Twin F-Body fans , With a temperature ground switch in the thermostat housing to trigger the relays at 160°. Simple system. I also have a 12 inch pusher that comes on when the AC is turned on. It triggers a third relay to come on.

 

[Longroof79]

Twin F-Body fans , With a temperature ground switch in the thermostat housing to trigger the relays at 160°. Simple system. I also have a 12 inch pusher that comes on when the AC is turned on. It triggers a third relay to come on.

I have a set of those that have been sitting on my shelf for several years now. I was deadset on using them until I decided to go old school using a clutch fan setup.

 

[tc1959]

I have a set of those that have been sitting on my shelf for several years now. I was deadset on using them until I decided to go old school using a clutch fan setup.

I went with the electric fans because of the heat here in Phoenix. When that fan clutch would come on it felt like I wat hauling 10,000 pounds. I never liked the way the AC would fall off at idle also. The electric fans keep the head pressure down in the AC system, so now it keeps cooling at idle.

 

[Longroof79]

I went with the electric fans because of the heat here in Phoenix. When that fan clutch would come on it felt like I wat hauling 10,000 pounds. I never liked the way the AC would fall off at idle also. The electric fans keep the head pressure down in the AC system, so now it keeps cooling at idle.

Paul,
At an idle, I'm sure the electric fans will out cool a standard clutch type fan....especially in your climate. After all, all late model cars use an electric fan setup.
I still have the option of going in that direction. Just need the relay setup, wire up a harness, and decide what type controller I'd use.
Roger1's setup is nice and neat....and it was nice of him to post a wiring diagram. Very well done, Roger.

 

[roger1]

Roger1's setup is nice and neat....and it was nice of him to post a wiring diagram. Very well done, Roger.

Thanks Jack.
Identical dual fans can be run in series which cuts their speed in half. If you looked at the 3-relay diagram you can see how the run the fans in series when the L wire is grounded and in parallel when both the L and H wires are grounded . The best thing about having them run half speed is they make almost no noise that way. The fully programmable Dakota PAC-2750 works really well for this too. It only requires one sender and if you have an aftermarket electric temperature gauge it will work with that. If not, you can buy one of their senders. In my case, I have the Dakota gauge cluster so the PAC-2750 plugs into that.
Another nice feature on the Dakota PAC-2750 is that you can put a trinary switch on your A/C high side line and have the fans come on at high speed when the head pressure goes to a certain pressure. The trinary switch I have kicks the fans on at 242 psi. There are many conditions where the A/C needs the air flow through the condenser but the engine coolant temperature is not hot enough to put the fans on high.