Aux fan Problem
Thread Starter
Pro
Joined: Sep 2003
Posts: 670
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From: charlotte nc
Aux fan Problem
I have an 86 A4 Z51. I dont think the aux fan in front of the AC condensor is working. Reason I say that is that I never hear or see it running. I have jumpered the fan and it does run , so I must have a sensor problem. Now for the embarassing part! I have a Helms manual but I have misplaced it somewhere and I have searched hi and lo and can't find it!!! 
Can someone give me the location of that fan sensor and how best to troubleshoot it. Thanks
Can someone give me the location of that fan sensor and how best to troubleshoot it. Thanks
Le Mans Master
Joined: Oct 2003
Posts: 6,130
Likes: 2
From: seattle WA
If it's the same as an 87 there is a temp switch on the drivers side
between cylinders 1 and 3 with a single wire, take it loose, turn the key to the on position and ground the wire-the fan should come on,
if it comes on now-but has not been coming on you need a new switch.
There's also a aux. fan relay on the drivers side by the radiator.
between cylinders 1 and 3 with a single wire, take it loose, turn the key to the on position and ground the wire-the fan should come on,
if it comes on now-but has not been coming on you need a new switch.
There's also a aux. fan relay on the drivers side by the radiator.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
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From: San Diego, Ca
Aux fan switch is located in the driver's side head and it will close at 228 degreeas which will complete the relay circuit and turn on the fan. It your cooling system is as good as it was when it left the factory, it will rarely if ever come on (plenty of Vettes left the Factory without it and cooled just fine). If you want to test it, jumper the switch harness to ground, or partially obstruct air flow - I test mine by putting the nose of the Vette close to the garage wall (when it's 90 or better) and then with the a/c off, I can usually get the temp high enough to close the switch. If you are seeing high temps and the aux fan is or isn't coming on, something else is wrong with the cooling system.
Team Owner
Joined: Sep 2001
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From: Athens AL
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Originally Posted by SunCr
Aux fan switch is located in the driver's side head and it will close at 228 degreeas which will complete the relay circuit and turn on the fan.
