Cooling fans

Tiny
NEWMAN39US
  • MEMBER
  • 2002 BUICK RENDEZVOUS
Engine Cooling problem 6 cyl Front Wheel Drive Automatic 130000 miles

My car is overheating and it appears that the 2nd cooling fan is not coming on. I have run direct power and it does work. I have checked fuses and relays and they are good. What should trigger the fan to come on?
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Monday, September 6th, 2010 AT 1:48 PM

9 Replies

Tiny
DOCFIXIT
  • EXPERT
Hi
There are three fan relays what grounds relay for high speed fan is the PCM. Also two cooling fan fuses. What method of testing relays was used?
Let me know
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Monday, September 6th, 2010 AT 2:00 PM
Tiny
NEWMAN39US
  • MEMBER
There are 4 relays that are the same in the engine comparment fuse box. I moved them to different positions with no change to anything so I assumed that is not the problem. Also swapped the 2 fuses. Is there a good way to check relays?
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Monday, September 6th, 2010 AT 2:09 PM
Tiny
DOCFIXIT
  • EXPERT
Swaping is good with know good relay. Then PCM controls relay so need scan tool to check if relay is being activated
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Monday, September 6th, 2010 AT 2:24 PM
Tiny
NEWMAN39US
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I will have that checked. Thanks for your help
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Monday, September 6th, 2010 AT 2:29 PM
Tiny
NEWMAN39US
  • MEMBER
One more question - when should the 2nd fan come on?
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Monday, September 6th, 2010 AT 2:57 PM
Tiny
DOCFIXIT
  • EXPERT
With AC and if coolant rises above 220 deg. If AC is Auto maybe AC conroler telling PCM AC is on.
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Monday, September 6th, 2010 AT 3:10 PM
Tiny
NEWMAN39US
  • MEMBER
Perfect -thanks very much for your help. Have a great day!
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Monday, September 6th, 2010 AT 3:14 PM
Tiny
CANDACE NICHOLS
  • MEMBER
The fans not coming on I think its a common ground I have ground to the left side fan but not to the drivers side fan and no ground to drivers side window as well I have no wiring diagram any clues?
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Tuesday, June 13th, 2017 AT 3:12 PM
Tiny
KEN
  • ADMIN
Hello,

I have found this cooling fan wiring diagram (below) for you and a guide to help you get the problem fixed.

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

and

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

Please run some tests and get back to us so we can continue helping you.

Cheers, Ken

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Friday, June 16th, 2017 AT 11:04 AM

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