Cooling fans, 1987
Thread Starter
3rd Gear
Joined: Mar 2003
Posts: 3
Likes: 0
From: Sierra Vista AZ
Cooling fans, 1987
Does anyone know, are there any concerns with electrically wiring both the pusher and puller fans together so they come on at the same time? Is there any problem running the puller fan above 35 MPH?
I understand the pusher is controlled by the temp swich on the block and A/C (I assume through the ECM). While the puller is controlled strictly by the ECM. I've tapped the puller ground that runs to the ECM to the ground of the pusher so when the A/C is on or the temp sensor reaches range, both fans come on. I thought this would be better than waiting for the ECM to turn on the puller at some 210 degrees, while the pusher struggles to keep thing cool. Any comments or suggestions? :flag
I understand the pusher is controlled by the temp swich on the block and A/C (I assume through the ECM). While the puller is controlled strictly by the ECM. I've tapped the puller ground that runs to the ECM to the ground of the pusher so when the A/C is on or the temp sensor reaches range, both fans come on. I thought this would be better than waiting for the ECM to turn on the puller at some 210 degrees, while the pusher struggles to keep thing cool. Any comments or suggestions? :flag
Drifting
Joined: Dec 2002
Posts: 1,861
Likes: 4
From: Houston TX
Re: Cooling fans, 1987 (canyonclimber)
I've had both of my fans wired together through a manual switch for 3-1/2 years, having both of them running at speeds as high as 145 on track with no problems.
Team Owner
Joined: Mar 2000
Posts: 83,383
Likes: 87
From: Boston, MA
Re: Cooling fans, 1987 (CorvetteZ51Racer)
I can never get the years right so I won't try now, but there are some years where the front fan supposedly won't come on over 35mph becuase it supposedly ends up hurting flow by creating a disturbance in front of the radiator not allowing air to flow smoothly at speed through the radiator.
What are your thoughts on that, Racer?
What are your thoughts on that, Racer?
Drifting
Joined: Dec 2002
Posts: 1,861
Likes: 4
From: Houston TX
Re: Cooling fans, 1987 (scorp508)
I can never get the years right so I won't try now, but there are some years where the front fan supposedly won't come on over 35mph becuase it supposedly ends up hurting flow by creating a disturbance in front of the radiator not allowing air to flow smoothly at speed through the radiator.
What are your thoughts on that, Racer?
What are your thoughts on that, Racer?
Burning Brakes
Joined: Feb 2000
Posts: 927
Likes: 0
From: Saginaw TX
Re: Cooling fans, 1987 (scorp508)
If I read the wiring schematic correctly the booster fan (front of rad) is controlled only by the thermostatic switch in the head. No input from ECM. Fan on back side of radiator is controlled only the the ECM based on A/C, speed and temp. I think stock booster fan on temp is around 235 deg. I have the fancy switch that allows me to manually turn on main fan or both fans. My 2 cents...
Thread Starter
3rd Gear
Joined: Mar 2003
Posts: 3
Likes: 0
From: Sierra Vista AZ
Re: Cooling fans, 1987 (canyonclimber)
I just wanted to let everyone know that I appreciate the input and I wanted to mention that I think the wiring schematic may be wrong in the book, at least for the 1987 model year. My pusher comes on when the A/C is tuned on, which tells me the wire from the temp sensor on the block stops someplace between there and the fan relay. I also couldn't get a good continuity reading when I checked the wire, another indicator that there is something in between them. In any event I'll run it up to Tucson or PHX in the next couple of weeks and if I don't see a difference I'll let everyone know.
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Verdad Gallardo
Team Owner
Joined: Dec 2000
Posts: 90,675
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From: SE NY
Cruise-In II Veteran
Re: Cooling fans, 1987 (canyonclimber)
On my '88 the aux fan is controlled directly and only by the aux fan sw in the left side of the block.
The main fan was controlled only by the ECM; when the A/C pressure sw opens the ECM brings on the fan.
I've been running both fans off a 160 deg aux fan sw for nearly two years with good results. My main concern is adequate cooling at the strip and in traffic and this setup works well. All I did was to splice a wire into the aux fan sw and run it to the main fan relay. The ECM can still kick on the fans if the A/C pressure goes too high, othewise the fans come on when coolant temp climbs over 160 deg.
The main fan was controlled only by the ECM; when the A/C pressure sw opens the ECM brings on the fan.
I've been running both fans off a 160 deg aux fan sw for nearly two years with good results. My main concern is adequate cooling at the strip and in traffic and this setup works well. All I did was to splice a wire into the aux fan sw and run it to the main fan relay. The ECM can still kick on the fans if the A/C pressure goes too high, othewise the fans come on when coolant temp climbs over 160 deg.
Thread Starter
3rd Gear
Joined: Mar 2003
Posts: 3
Likes: 0
From: Sierra Vista AZ
Re: Cooling fans, 1987 (canyonclimber)
65Z01 That's how I wired mine. Questions: your 160 temp switch, did you replace your chip also or just the temp switch. From what I've seen the catologs tell you you must replace the chip, switch, and t-stat for things to run right?
