AUX fan?
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Instructor
Joined: Mar 2002
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From: yardley pa
AUX fan?
When is the the small fan in front of the radiator supposed to come on? My main fan came on and i looked under the hood just out of curosity and noticed the small fan wasnt on. Is there a way to test the fan motor or to see if it works? Thanks Ron
Team Owner
Joined: Mar 2000
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From: Boston, MA
I'm pretty sure that in 1984 it only came on under 35mph (I forget the temps though). I'm not sure about us. :) If you want to test it... with the key on, ground the terminal that the green wire with a white stripe goes into on the relay for it.
Drifting
Joined: Nov 2001
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From: Latham NY
Re: AUX fan? (siberianhusky911)
On my 85 the front fan is controlled by a coolant temperature switch in the block. Stock comes on around 220? There is also a relay involved. Ground the green wire on the relay and the fan should turn on. I replaced it with a 195 degree switch from Zip and 180 degree stat and connected the green wires from both fan relays together so they both come on together.
[Modified by Bluevette85, 6:44 PM 3/29/2002]
[Modified by Bluevette85, 6:44 PM 3/29/2002]
Team Owner
Joined: Dec 2000
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From: SE NY
Cruise-In II Veteran
Re: AUX fan? (siberianhusky911)
It's more of a safety device and comes on at very high temp, 228deg F (on my '88). It's controlled by the digital aux fan sw in the left block between #1 & #3 plugs (again on my '88).
To test it, pull the connector to that sw and, with the ignition On, ground the wire to turn on the aux fan relay.
I installed a 160 deg aux fan sw (to compliment my 160 deg stat) and used cable splicers and a short run of wire from Radio Shack to also turn on both my main fan and the aux fan at that temp.
To test it, pull the connector to that sw and, with the ignition On, ground the wire to turn on the aux fan relay.
I installed a 160 deg aux fan sw (to compliment my 160 deg stat) and used cable splicers and a short run of wire from Radio Shack to also turn on both my main fan and the aux fan at that temp.
Team Owner
Joined: Mar 2001
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From: Cincinnati, Oh USA
Re: AUX fan? (siberianhusky911)
The aux fan comes on at 238 F and the thermal switch between cylinders 1 and 3 turns it on. Other switches with lower closing temperatures are available.
238 F won't hurt your engine, but you should look into why it is getting there. Be sure to clean the debris off the radiator front . I blast water backwards through the radiator and then through the gap around the radiator cap.
238 F won't hurt your engine, but you should look into why it is getting there. Be sure to clean the debris off the radiator front . I blast water backwards through the radiator and then through the gap around the radiator cap.
