Irratic fan problems
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Melting Slicks
Joined: Oct 2000
Posts: 2,019
Likes: 2
From: Na
Irratic fan problems
I have a problem with my electric fan. You see, It turns on whenever it feels like it. Sometimes it turns on right as I start the car up in the morning. Other times it turns on when coolant temp. is around 140 and 180. What gives? Do I have a bad relay or something? Can it be a problem with the computer? Help me out. Thanks.
Le Mans Master
Joined: Aug 2000
Posts: 5,192
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From: Airport Cruise-in 1 Veteran Airport Cruise-in 2 Veteran
Cruise-In II Veteran
Re: Irratic fan problems (NUckINg FuTS)
This is going by my 87 manual.
Try disconnecting the fan relay and see if it stops or keeps going. If it stops it could be a short in the DRK GRN/WHT wire, faulty ECM or a faulty relay and if it doesn't it could be a shorted BLU/PNK wire. Not sure if the wire colors are the same for 86 and 87 but HTH.
[Modified by War Machine, 11:06 AM 5/10/2002]
Try disconnecting the fan relay and see if it stops or keeps going. If it stops it could be a short in the DRK GRN/WHT wire, faulty ECM or a faulty relay and if it doesn't it could be a shorted BLU/PNK wire. Not sure if the wire colors are the same for 86 and 87 but HTH.
[Modified by War Machine, 11:06 AM 5/10/2002]
Safety Car
Joined: Feb 2002
Posts: 4,212
Likes: 10
From: Sun City West Az
Re: Irratic fan problems (NUckINg FuTS)
Another thing you might look at is the A/C pressure sensor. If it is out of range, it will cause the fans to operate at the wrong times. As th eother post mentions, it could be a short to ground causing the relays to close. In the 92 manual, its the dark blue/white and dark green/white from the relays.
Burning Brakes
Joined: Feb 2000
Posts: 824
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From: Camden SC
Re: Irratic fan problems (NUckINg FuTS)
I'll start with the simple and cheap. Check the resistance on your engine coolant temp sensor and compare with the value in the service manual. Not sure about the 86 but suspect the computer (ECM)provides the ground for the fan relay based on temperature signal from the coolant temp sensor. They are a negative temperature coefficient thermistor and can get out of whack. Be sure to use a pretty good digitial volt ohm meter (DVOM).
Keep the faith.
dlmeyers 90 coupe zf6 3 speed shocks
Keep the faith.
dlmeyers 90 coupe zf6 3 speed shocks
