Coolant fans will not run

Smith28851
0

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?

1 Answer

Seth Stultz
65

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 out of 1 people think this is helpful.

Your Answer

Add photo

Related Questions

  • radiator engine fans not running 1 answer

    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

  • 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

  • cooling issues, fans wont start 7 answers

    98 grand prix,3.8,. had a blown head gasket, removed the heads had a valve job done, and replaced all gaskets involved with replacing the heads. also replaced radiator, water pump, tstat, ect sensor, ...

    Pontiac Grand Prix

    -

    Maintenance & Repair

  • filling the radiator with coolant 1 answer

    Hi, i have had to replace the water pump on my 1995 Grand Prix SE with a 3.1L motor, there is a sticker by the radiator cap that says that there is a certain way to fill this system or there could be ...

    1995 Pontiac Grand Prix 2 Dr SE Coupe

    -

    Maintenance & Repair

  • Engine cooling fan won't run ,but motor is good 1 answer

    The engine cooling fan is good ,and I replaced 1 relay, and the coolant temp sensor, but the fan will still not run even with A/C on ,or when engine reaches temp.

    1991 Pontiac Trans Sport

    -

    Maintenance & Repair

Search Pontiac Grand Prix Questions

Pontiac Grand Prix Experts

#1 Js08016
Js08016
Reputation 1,590
#2 Tom Demyan
Tom Demyan
Reputation 1,270
#3 John Saffrahn
John Saffrahn
Reputation 910
View All

Related Models For Sale

Used Chevrolet Impala"
1,704 Great Deals out of 58,445 listings starting at $995
Used Pontiac Bonneville"
39 Great Deals out of 1,045 listings starting at $1,995
Used Pontiac Grand Am"
55 Great Deals out of 2,502 listings starting at $1,200
Used Chevrolet Monte Carlo"
70 Great Deals out of 2,420 listings starting at $1,595
Used Ford Mustang"
1,017 Great Deals out of 25,478 listings starting at $1,329
Used Chevrolet Camaro"
617 Great Deals out of 28,537 listings starting at $1,795
Used Nissan Altima"
1,530 Great Deals out of 79,560 listings starting at $995
Used Nissan Maxima"
621 Great Deals out of 19,471 listings starting at $1,495
Used Jeep Grand Cherokee"
1,102 Great Deals out of 54,419 listings starting at $1,100
Used Honda Accord"
1,259 Great Deals out of 65,756 listings starting at $1,000

Used Cars For Sale

2008 Pontiac Grand Prix For Sale
32 Great Deals out of 685 listings starting at $4,499
2007 Pontiac Grand Prix For Sale
31 Great Deals out of 715 listings starting at $2,980
2006 Pontiac Grand Prix For Sale
28 Great Deals out of 747 listings starting at $2,950
2005 Pontiac Grand Prix For Sale
21 Great Deals out of 578 listings starting at $2,753
2004 Pontiac Grand Prix For Sale
39 Great Deals out of 881 listings starting at $1,995