Auxiliary fan missing.
Thread Starter
Intermediate
Joined: Mar 2011
Posts: 26
Likes: 0
Auxiliary fan missing.
The auxiliary fan is either missing or never was on my 86. It tends to run too hot in the summer months.
I'd like to install an auxiliary fan but I don't have the mounting hardware. I see the after-market fans are secured to the front of the air conditioning condenser with plastic ties that I'm guessing, run right through the condenser and out the radiator on the other side.
I'm wondering how well this works? Also, should I purchase a pusher or puller fan.
Thank-You for the advice.
I'd like to install an auxiliary fan but I don't have the mounting hardware. I see the after-market fans are secured to the front of the air conditioning condenser with plastic ties that I'm guessing, run right through the condenser and out the radiator on the other side.
I'm wondering how well this works? Also, should I purchase a pusher or puller fan.
Thank-You for the advice.
Last edited by 86redcorvette; Apr 29, 2014 at 09:01 PM.
Safety Car
Joined: Aug 2009
Posts: 3,751
Likes: 276
From: Melbourne, Victoria, Australia
The auxiliary fan is either missing or never was on my 86. It tends to run too hot in the summer months.
I'd like to install an auxiliary fan but I don't have the mounting hardware. I see the after-market fans are secured to the front of the air conditioning condenser with plastic ties that I'm guessing, run right through the condenser and out the radiator on the other side.
I'm wondering how well this works? Also, should I purchase a pusher or puller fan.
Thank-You for the advice.
I'd like to install an auxiliary fan but I don't have the mounting hardware. I see the after-market fans are secured to the front of the air conditioning condenser with plastic ties that I'm guessing, run right through the condenser and out the radiator on the other side.
I'm wondering how well this works? Also, should I purchase a pusher or puller fan.
Thank-You for the advice.
All you need to do is connect a ground wire to one side to the t/stat, and run a wire to the cooling fan relay where the ecm grounds the relay. I believe it is a small green and white wire .
On the cars with the optional booster fan, that is controlled by a switch in the head and is set to activate at 239F (115c)
I think the single cooling fan have the head switch as an override if the ECM fails.
See diagram
Last edited by gerardvg; Apr 29, 2014 at 11:44 PM.
Pro
Joined: Oct 2003
Posts: 550
Likes: 0
From: Hesperia California
On my 89, I replaced the worthless aux. fan with a black max pusher. came with the plastic strips that go through radiator. Been there for years. I also put an aux. fan switch on so I can turn on both fans when I want them. Helps in the summer.
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Thread Starter
Intermediate
Joined: Mar 2011
Posts: 26
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I will google this "black max" and see if I can find it. I've already installed the switch which turns the fan on at 195. Car runs around 198-205 except during the summer where it will only cool once you leave the light and with lots of lights the car quickly heats up. I've had it hit 240, 245, 250, warning light comes on, 260 was the farthest I've pushed this fairly new motor (25,000) and would hate to lose a head gasket.
230 is just to hot period so I want an auxiliary fan but was suspicious of putting one on with plastic ties.
I imagine the reason for the auxiliary fan is because 1 just doesn't get the job done.
Safety Car
Joined: Jan 2004
Posts: 3,783
Likes: 15
From: Northern California
Install a "Spal" Puller fan and you'll be good to go.
Spal fan cfm's are rated under load, compared to a lot of aftermarket fans which are rated in free air.
Nylon ties, work great for securing aftermarket fans.
Spal fan cfm's are rated under load, compared to a lot of aftermarket fans which are rated in free air.
Nylon ties, work great for securing aftermarket fans.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Initially a Dealer installed option following overheating complaints from racers and high altitude users - never meant for much else and it isn't necessary unless you're about to tackle Pike's Peak.
C4's didn't come from the Factory with a cooling defect; in fact there was quite a bit of hot weather testing in Arizona.
Airflow from the single fan through the radiator should drop the temperature; if not something isn't right. Causes include a broken or mis-positioned shroud; worn out fan motor; weak alternator/battery; weeping head gasket and/or lean idle mix; and a plugged up/worn out radiator and/or cap. Given the low amp idle output of the stock alternator (up until about '89), running both fans can lead to overheating as there isn't enough juice for both fans and when they slow down it will heat up. Making sure everything is the way it left the Factory will keep it in specs and if you want it to run cooler, turn on the a/c (though that has to be right too). The single fan will then keep the liquid in the Condenser well below the thermostat (or if it doesn't it will blow a hole in the hood) and your temps will be 10 to 12 degrees less than if it were off.
C4's didn't come from the Factory with a cooling defect; in fact there was quite a bit of hot weather testing in Arizona.
Airflow from the single fan through the radiator should drop the temperature; if not something isn't right. Causes include a broken or mis-positioned shroud; worn out fan motor; weak alternator/battery; weeping head gasket and/or lean idle mix; and a plugged up/worn out radiator and/or cap. Given the low amp idle output of the stock alternator (up until about '89), running both fans can lead to overheating as there isn't enough juice for both fans and when they slow down it will heat up. Making sure everything is the way it left the Factory will keep it in specs and if you want it to run cooler, turn on the a/c (though that has to be right too). The single fan will then keep the liquid in the Condenser well below the thermostat (or if it doesn't it will blow a hole in the hood) and your temps will be 10 to 12 degrees less than if it were off.
Melting Slicks
Joined: May 2010
Posts: 2,082
Likes: 3
From: Conowingo Maryland
Initially a Dealer installed option following overheating complaints from racers and high altitude users - never meant for much else and it isn't necessary unless you're about to tackle Pike's Peak.
C4's didn't come from the Factory with a cooling defect; in fact there was quite a bit of hot weather testing in Arizona.
Airflow from the single fan through the radiator should drop the temperature; if not something isn't right. Causes include a broken or mis-positioned shroud; worn out fan motor; weak alternator/battery; weeping head gasket and/or lean idle mix; and a plugged up/worn out radiator and/or cap. Given the low amp idle output of the stock alternator (up until about '89), running both fans can lead to overheating as there isn't enough juice for both fans and when they slow down it will heat up. Making sure everything is the way it left the Factory will keep it in specs and if you want it to run cooler, turn on the a/c (though that has to be right too). The single fan will then keep the liquid in the Condenser well below the thermostat (or if it doesn't it will blow a hole in the hood) and your temps will be 10 to 12 degrees less than if it were off.
C4's didn't come from the Factory with a cooling defect; in fact there was quite a bit of hot weather testing in Arizona.
Airflow from the single fan through the radiator should drop the temperature; if not something isn't right. Causes include a broken or mis-positioned shroud; worn out fan motor; weak alternator/battery; weeping head gasket and/or lean idle mix; and a plugged up/worn out radiator and/or cap. Given the low amp idle output of the stock alternator (up until about '89), running both fans can lead to overheating as there isn't enough juice for both fans and when they slow down it will heat up. Making sure everything is the way it left the Factory will keep it in specs and if you want it to run cooler, turn on the a/c (though that has to be right too). The single fan will then keep the liquid in the Condenser well below the thermostat (or if it doesn't it will blow a hole in the hood) and your temps will be 10 to 12 degrees less than if it were off.
That is one thing with these cars and on this board where I get lost. For the most part GM knows what they are doing. And so many want to fix something that is not a problem. I cannot remember what yrs the temps went up but it was in the mid 70s. So just about every car from that point have been running close to what we see with the C4 and so on. It was just never questioned because there was not lcd screen yelling what the temp was. We had a gauge and as long as proplr were not in the red who cared. In the 70 the fanous clutch fan came out to save fuel. I did so by not locking up untill a certain temp. Quess what people that temp for full lock up was about 230. Right about where or electric fans come on now. So in reality most all manfactures have been running the same temps we see sense the mid 70. They have not hurt anything in all this time why does there seem a need to change?