Coolant fans will not run

Asked by Smith28851 May 24, 2011 at 08:13 PM about the 1994 Pontiac Grand Prix 4 Dr SE Sedan

Question type: Maintenance & Repair

I have a 3.1L with 170000 miles. I recently replaced the intake manifold and upper plenum gaskets along with thermostat.  While bleading the air from the system the car became very warm, almost redline before shutting it down.  The fans never came on.  I have checked the fans, they run fine. I have checked both the primary and secondary relays, thay work as well.  Checked for power at the relay both the power side and coil side have power at the relays.  One latch side is hot in run and the other is hot all of the time. I checked the control voltage at the temp sensor plug it is at 5 volts.  I have checked the resistance acorss the sensor it is 3000 ohms at 80 degrees and in the 200 ohm range when the termostat opens.  When I start the car and unplug the temp sensor connector to create an open loop situation both fan come on. They will not come on with the A/C on max with the blower on high either. Is there a way that I can verify if the ECM is latching the fan relay closed or maybe something I have overlooked?

2 Answers
165

Seth answered 13 years ago

as a certified technisian the only way to test the ecm to make sure its doing is to plug it into a scan tool and look at the display screen of whats all running and testing setup on the scan tool and maybe manually turn on the fans and if that works the ecm is definitely in need of replacement. but be carefull and make sure to wear the ground strap they give you to install it with. ive installed a ecm in my wifes 97 and fried the first one without wearing the strap they provided me with. wont do that again. and the 3.1 is a good engine. just take care of her and shell take care of you. thats all i got hopefully it helps. you might have to go to a shop and have then do that. which is about 80 to 100$ depending on the shop. so good luck

1 people found this helpful.
Mark helpful
10

Wayne answered 9 years ago

Just replaced water pump on 94 Gran Prix and not the one fan closer to water pump won't come on

1 people found this helpful.
Mark helpful

Your Answer:

Related Questions

  • Coolant fans will not run 2 Answers

    I have a 3.1L with 170000 miles. I recently replaced the intake manifold and upper plenum gaskets along with thermostat. While bleading the air from the system the car became very warm, almost redlin...

    1994 Pontiac Grand Prix 4 Dr SE Sedan

    -

    Maintenance & Repair

  • cooling fans do not run 1 Answer

    engine runs hotter than normal when sitting in traffic and the fans do not come on

    2004 Pontiac Grand Prix GT1

    -

    Maintenance & Repair

  • Coolant fans 1 Answer

    Hi my name is Holden and I’m currently having trouble because my coolant fans wont kick on for my 3100. As far as things I’ve done I’ve, replaced head gaskets, cleaned out coolant ports, replaced ...

    2001 Pontiac Grand Prix SE

    -

    Maintenance & Repair

  • 2005 Grand Prix coolant fans not working 3 Answers

    2005 Grand Prix base 100,500 mile The a/c does not turn on the fans. The temp gauge on the dash is correct well seems to be in correlation with a the reading from a infrared thermometer, the relay...

    2005 Pontiac Grand Prix Base

    -

    Maintenance & Repair

  • radiator engine fans not running 3 Answers

    im back i got my car running good and now the fans have stopped running causing the car to overheat again. What can I do to make sure that the fans need changed before spending the money for new one...

    2004 Pontiac Grand Prix GTP

    -

    Maintenance & Repair

Shortcuts

Search Pontiac Grand Prix Questions

CarGurus Experts

  • #1
    munron
    Reputation
    8,230
  • #2
    James Sparrow
    Reputation
    7,530
  • #3
    Dorian Hendricks
    Reputation
    6,190
View All

Find great deals from top-rated dealers

Search

Related Models For Sale

Used Pontiac Bonneville
1 listing
Used Chevrolet Impala
6 Great Deals out of 94 listings starting at $3,495
Used Chevrolet Camaro
20 Great Deals out of 281 listings starting at $7,995
Used Pontiac Grand Am
1 listing
Used Ford Mustang
58 Great Deals out of 1,366 listings starting at $4,995
Used Pontiac Firebird
14 listings
Used Chevrolet Corvette
27 Great Deals out of 1,082 listings starting at $15,000
Used Buick Regal
3 Great Deals out of 39 listings starting at $4,991
Used Chevrolet Monte Carlo
5 listings starting at $9,449
Used Jeep Grand Cherokee
109 Great Deals out of 3,136 listings starting at $3,995

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use. Content will be removed if CarGurus becomes aware that it violates our policies.