CHECKING AUXILLIARY FAN
Thread Starter
Heel & Toe
Joined: Jan 2001
Posts: 22
Likes: 0
From: HANOVER, PA. USA
CHECKING AUXILLIARY FAN
I HAVE AN 89 AND FOUND THE AUX FAN IN FRONT OF THE RADIATOR. I LET THE CAR WARM TO ABOUT 230 DEGREES AND THE MAIN FAN CAME ON. I PUT ON THE A/C BUT THE AUX FAN DID NOT COME ON. PLEASE TELL ME HOW I MAY CHECK TO SEE IF THE FAN WORKS OR NOT AND HOW DO I TELL IT'S NOT THE RELAY?
THANKS FOR YOUR HELP
[Modified by BLKBTY, 11:52 AM 8/30/2001]
THANKS FOR YOUR HELP
[Modified by BLKBTY, 11:52 AM 8/30/2001]
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: CHECKING AUXILLIARY FAN (BLKBTY)
The aux fan is only controlled by the digital aux fan sw in the left side of the block between #1 & #3 plugs.
This sw is set to close the contact (grounding it) at 228deg F, but could be off a little.
To test the aux fan relay (located on the left side of the radiator shroud) unplug the connector to the aux fan sw and jumper the contact to ground and turn on the ignition sw. If you do this when the motor is cold you will hear only the aux fan running instead of the louder main fan.
This sw is set to close the contact (grounding it) at 228deg F, but could be off a little.
To test the aux fan relay (located on the left side of the radiator shroud) unplug the connector to the aux fan sw and jumper the contact to ground and turn on the ignition sw. If you do this when the motor is cold you will hear only the aux fan running instead of the louder main fan.
Burning Brakes
Joined: Nov 2000
Posts: 855
Likes: 0
Re: CHECKING AUXILLIARY FAN (65Z01)
If you test using 65Z01 method and it comes on, then it is the switch in the head that is bad, and if you want you can splice that wire to a perminent ground and put a switch inline to operate the fan manually. That is what I did.
Team Owner
Joined: Mar 1999
Posts: 89,144
Likes: 3
From: Life's tough, wear a helmet.
Re: CHECKING AUXILLIARY FAN (65Z01)
This sw is set to close the contact (grounding it) at 228deg F, but could be off a little.
I've checked my aux fan using the grounding method above and it works. But as far as I know it's never come on by itself.
