Radiator fans not working

Tiny
LAURIE DAVIS
  • MEMBER
  • 2003 PONTIAC MONTANA
  • 3.4L
  • 6 CYL
  • AUTOMATIC
  • 169,000 MILES
The fans do not come on. I have installed new sensor and all relays the fans are not locked up. The fans will operate when using a jump wire. This caused the overheated engine to blow a head gasket I have replaced the gaskets recommended and reassembled the motor. Vehicle is running as it did prior to the blown gasket. I fear it will blow the gasket again. Diagnostics has been done and each time I replace the parts it indicates is the problem, retesting gives a new different result. I have done everything but still the fans do not come on. What else could be the problem? How do I fix it?
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Tuesday, April 25th, 2017 AT 10:31 AM

9 Replies

Tiny
HMAC300
  • EXPERT
First thing to do is check fuse with a test light/volt meter if that is good then pull the relay in picture and check for corrosion on prong. Try to clean it off if any, and tweak it a tad then use dielectric grease, about $2.00 at auto part called bulb grease. If not that check fuse box and check green wire with test light when hot to see if PCM is telling relay to turn on. Also, check where relay plugs in to see if power comes in. One other thing when A/C is turned on other fan should work so do same on those wires in picture. This may be a fuse box problem. If everything else is working okay.
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Tuesday, April 25th, 2017 AT 12:22 PM
Tiny
ART SMITH
  • MEMBER
  • 2000 PONTIAC MONTANA
Two wheel drive automatic.

Fans not working fuse okay. How do I check further?
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Tuesday, July 24th, 2018 AT 10:29 AM (Merged)
Tiny
SATURNTECH9
  • EXPERT


http://www.2carpros.com/forum/automotive_pictures/416332_2000_pontiac_coolant_temp_sensor_1.jpg


I posted a diagram of where the coolant temperature sensor is unplug it and with the engine idling jump the two terminal's together on the connector harness with a jumper wire. If the fan kick's on replace the coolant temperature sensor.
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Tuesday, July 24th, 2018 AT 10:29 AM (Merged)
Tiny
JOEYB69
  • MEMBER
  • 2000 PONTIAC MONTANA
  • 6 CYL
  • FWD
  • 64,000 MILES
The radiator fan is not working. I have replaced the fuse.
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Tuesday, July 24th, 2018 AT 10:29 AM (Merged)
Tiny
RASMATAZ
  • MEMBER
Check and test the fan relay and the coolant temperature sensor.
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Tuesday, July 24th, 2018 AT 10:29 AM (Merged)
Tiny
BAROSJOEY
  • MEMBER
  • 1999 PONTIAC MONTANA
Six cylinder two wheel drive automatic.

Cooling fans do not kick on. Only when you turn on A/C. Already changed thermostat and sensor on housing also changed both fan relays.
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Tuesday, July 24th, 2018 AT 10:29 AM (Merged)
Tiny
BLUELIGHTNIN6
  • EXPERT
There are three relays and two maxi fuses that need to be checked. Here is a guide to help you test the relays and a wiring diagram so you can see how the system works:

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

and to test the wiring:

https://www.2carpros.com/articles/how-to-check-wiring

Use the test light to check for power at the relay.

Check out the diagrams (below). Please let us know what happens.

Cheers
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Tuesday, July 24th, 2018 AT 10:29 AM (Merged)
Tiny
BAROSJOEY
  • MEMBER
Thanks for your help on this. It turned out the fan control driver was out in the PCM. So I got a used one and plugged it in all fixed! I love this site.
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Tuesday, July 24th, 2018 AT 10:29 AM (Merged)
Tiny
BLUELIGHTNIN6
  • EXPERT
Good to hear, please use 2CarPros anytime we are here to help.

Cheers
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Tuesday, July 24th, 2018 AT 10:29 AM (Merged)

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