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Pusher Fan help

H

holdenjp

New member
Joined
Oct 24, 2012
Location
Indiana
1991 245 Turbo, automatic

Okay, I've been looking all day and can't find quite what I'm looking for.

I have been stuck in traffic a few times lately and my temperature gauge has climbed all the way up to red. Seems to come back down just fine if I get some clean air in front of me and can drive for a few minutes. However, when I turn on the A/C even on the interstate with lots of air moving over the condensor and radiator my temps climb up to red again and I have to turn it off. I checked today and my pusher fan does come on after a minute or so of the A/C coming on and I get cold air in the cabin of the car.

This all brings me to my current conclusion. I want my pusher fan to come on when temps climb to help keep the engine cool when I'm stuck in traffic or temps get too high.

I've checked the wiring diagram and it appears that it will only currently come on when the A/C is on and creates pressure. I don't want to do an electric fan conversion.

Can I wire the pusher fan to come on when the engine temps get too high? Seems like I should be able to use a Saab fitting in the lower radiator hose, but I wondered if I could install a radiator from another year/model with a thermostat switch already installed.
 
B230ft swap, b230f+t..?

1991 cars should have the pusher fan that SHOULD come on when AC pressures get too high (or too hot, but pressure is heat ya know). The factory pusher fan does a fantastic job at keeping my 1993 245 na car cool, with the AC on and obviously with the help of the puller fan.

Something I've noticed in my 244+t is that driving on the highway with a late model condenser, fat npr intercooler, stock radiator, and a 940 efan is that the air really struggled to pass through all of the cores. Are you using a proper fan shroud? If you use an intercooler you'll either need an efan or the narrow 240tic fan shroud. Without a shroud you're ****ed in the hot weather!

FWIW, I installed a spal 14" pusher on the front of my condenser. It moves enough air and doesn't draw **** for current. I just plugged it into the factory 2 wires for the factory pusher fan. Comes on when it needs to. Something to keep in mind, that fan will not come on if AC pressures are too low. You need to make sure your system has sufficient freon otherwise that fan won't come on.

Also I have the 940 fan high speed on a switch and I kinda just have to always keep it on during warmer days. Talk about cold AC!

If you want you can make your stock pusher fan on a switch.
 
PromiseRing said:
Wait wait wait....check the fundamentals. Does your clutch fan function as it should? Is your temp board bypassed?
Click to expand...

I don't know how to check the fan clutch.

I don't think the temp board is bypassed, but I guess I also don't know how to check that either. All of the wiring in the car seems to be stock.
 
To check the fan clutch, get the engine hot, then turn it off. Fan should be very stiff to turn. It it just spins, your fan clutch is toast
 
cwdodson88 said:
get a good puller e-fan and shroud, Saab T or something else.. gain some power, lose some weight, stay cooler... win win win
Click to expand...

I will respectfully disagree. A good functioning mechanical fan will outperform an efan most of the time. It's more reliable. You will also want a good pusher to go with the setup.

OP what are you using for a fan shroud for the mechanical fan? Show us. If you have an intercooler you need the proper shroud. E fan is always an option but it needs to be setup very reliably and correct.
 
There should be no need for a puller fan to cool your radiator/engine. Diagnose the problem that is causing the temp gauge to rise. I have lived in climates on 100f+ temps with a mechanical fan only and never had a problem with the temp gauge rising.
 
I had this exact problem, washing the radiator fixed it. Hose it really good from the inside of the engine bay so you push everything out.
 
snailpoweredbrick said:
There should be no need for a puller fan to cool your radiator/engine. Diagnose the problem that is causing the temp gauge to rise. I have lived in climates on 100f+ temps with a mechanical fan only and never had a problem with the temp gauge rising.
Click to expand...

I assume you meant pusher fan. I will also disagree with you on this. I like to think i know a fair amount about cooling systems on 240s/ fans needed etc. I've done many many trial and errors.

On a 240 with the ac off, it will never overheat assuming the fan clutch, thermostat, rad, WP etc are working properly. At idle the fan only moves x amount of air. The CFM of air drawn through the radiator increases with rpm. At idle, that mechanical fan (WITH AC OFF) will move enough air through the rad to keep it at 180F when it's 100F outside.

When you turn on the ac you introduce another heat exchanger (like a radiator). You're basically depending upon that puller fan at idle to cool down 2 'radiators'. When you draw hot condenser air through your radiator, temps have problems keeping cool. This is where the pusher fan comes into play. It will come on when AC system pressures are too high and it will dissipate heat from the condenser. That paired with the puller fan at idle has kept my car well under 200F in the 100F ambient air.

OP, once again, are you using a shroud? An unshrouded mechanical fan along with a pusher will not be enough to keep the car cool on hot days. You want to draw air THROUGH the radiator not AROUND it.
 
5ft24 said:
To check the fan clutch, get the engine hot, then turn it off. Fan should be very stiff to turn. It it just spins, your fan clutch is toast
Click to expand...

Checked the fan before driving and after driving for about 20 minutes. The resistance kept the fan from spinning much at all with me trying to spin it. And it seemed about the same before and after driving.
 
Last edited:
Possibly dumb question, but I'm pretty sure the fan clutch that is on the car is from N/A car not a turbo. Is it possible that the N/A clutch can't keep up for some reason?
 
The coolant temp gauge should not go into the red when the AC is turned on if everything is working correctly. I agree a pusher fan with help cool the radiator, intercooler and condenser, but it is not required to keep the coolant temp gauge in the middle. If that was true every 1980's 240 would need a pusher fan to be able to operate the AC without overheating.
 
You can check the fan clutch by letting your car sit there an idle for 20 minutes or so that way the engine is at full temp. (If it overheats just sitting there don't let it do that) the fan clutch will 'engage' when it gets hot enough and you should NOT be able to stop the blades. When revved it should make a very loud whoosh noise and the fan should not free wheel.

Upon a cold start the fan is engaged, it disengages after 30 seconds of driving. Once the airflow over the clutch is hot enough it will re engage and draw more air. You need to make sure the fan clutch engages.
 
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