The "other" cooling fan
Thread Starter
Racer
Joined: Jun 2002
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From: Palm City FL
The "other" cooling fan
I've noticed that when my engine (on occasion) hits that 220 mark, my secondary cooling fan does not go on.
When i ground the wire on the secondary fan relay, it kicks on. There is a sensor on the block between the 6&8 cyl and I was told that it controls the secondary fan. When I ground that, nothing happens.
Does this run off the ecm or the sensor?
When i ground the wire on the secondary fan relay, it kicks on. There is a sensor on the block between the 6&8 cyl and I was told that it controls the secondary fan. When I ground that, nothing happens.
Does this run off the ecm or the sensor?
Team Owner
Joined: Sep 2001
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Re: The "other" cooling fan (severe-1)
The Aux fan is not controlled by the ECM.
Its either that sensor or a relay. It shouldnt come on til about 238F though, unless you wired in a switch or something.
Its either that sensor or a relay. It shouldnt come on til about 238F though, unless you wired in a switch or something.
Thread Starter
Racer
Joined: Jun 2002
Posts: 411
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From: Palm City FL
Re: The "other" cooling fan (vader86)
I already swapped relays just to test. Same thing. If the sensor was bad, wouldn't it come on if I grounded that wire?
For that matter, am I playing w/the right sensor?
For that matter, am I playing w/the right sensor?
Team Owner
Joined: Sep 2001
Posts: 62,160
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Re: The "other" cooling fan (severe-1)
I think the aux fan relay is mounted on the left side of the radiator.
If power and ground is ok, somethin is up with the fan.
If you disconnected the switch, and then grounded it, one of the fans shouldve come on. But, ground the terminal 'B' in the relay with the ignition in the ON position, and if it doesnt work, then there may be broken link somewhere in the circuit. Either that or a fuse, if there is one for that, i dont even know if there is.
Thats all that comes to mind
[Modified by vader86, 11:49 PM 7/2/2003]
If power and ground is ok, somethin is up with the fan.
If you disconnected the switch, and then grounded it, one of the fans shouldve come on. But, ground the terminal 'B' in the relay with the ignition in the ON position, and if it doesnt work, then there may be broken link somewhere in the circuit. Either that or a fuse, if there is one for that, i dont even know if there is.
Thats all that comes to mind
[Modified by vader86, 11:49 PM 7/2/2003]
Instructor
Joined: Jan 2002
Posts: 221
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From: League city Texas
Re: The "other" cooling fan (severe-1)
What year Vette do you have? This makes a differance since the General move the aux. cooling fan switch to different locations over the years. My 85 is between cyls 6 & 8.
Team Owner
Joined: Mar 2001
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From: Cincinnati, Oh USA
Re: The "other" cooling fan (severe-1)
The aux fan is controlled by a thermostatic switch on the LEFT side of the block between cylinders #1 and #3 and turns on the aux fan at 238 F by grounding its green wire. The sensor on the RIGHT side of the block is a sensor that operates ONLY the temp gauge in the cluster, nothing else.
Le Mans Master
Joined: Dec 1999
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From: And on the fifth day, subpoenas were served to Obama senior staff
Re: The "other" cooling fan (jfb)
The aux fan is controlled by a thermostatic switch on the LEFT side of the block between cylinders #1 and #3 and turns on the aux fan at 238 F by grounding its green wire. The sensor on the RIGHT side of the block is a sensor that operates ONLY the temp gauge in the cluster, nothing else.
A good guess on the 86 might be: early 86 (iron head) between 8 and 6; late 86 (aluminum head - center bolt valve covers) between 1 and 3. Don't know if this is true.
Pete
