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?

2 Answers

Seth Stultz
75

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.
Wayne Chambers
0

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

Your Answer

Add photo

Related Questions

Search Pontiac Grand Prix Questions

Pontiac Grand Prix Experts

#1 Js08016
Js08016
Reputation 2,380
#2 Tom Demyan
Tom Demyan
Reputation 1,740
#3 John Saffrahn
John Saffrahn
Reputation 1,190
View All

Related Models For Sale

Used Chevrolet Impala"
1,496 Great Deals out of 55,955 listings starting at $1,399
Used Chevrolet Monte Carlo"
59 Great Deals out of 1,790 listings starting at $1,500
Used Pontiac Bonneville"
12 Great Deals out of 731 listings starting at $1,200
Used Pontiac Grand Am"
13 Great Deals out of 1,969 listings starting at $1,591
Used Ford Mustang"
651 Great Deals out of 33,489 listings starting at $1,595
Used Nissan Altima"
1,278 Great Deals out of 79,099 listings starting at $1,495
Used Chevrolet Camaro"
492 Great Deals out of 34,395 listings starting at $1,400
Used Nissan Maxima"
416 Great Deals out of 16,178 listings starting at $2,250
Used Honda Accord"
1,092 Great Deals out of 69,170 listings starting at $500
Used Jeep Grand Cherokee"
823 Great Deals out of 57,237 listings starting at $1,995

Used Cars For Sale

2008 Pontiac Grand Prix For Sale
14 Great Deals out of 550 listings starting at $3,950
2007 Pontiac Grand Prix For Sale
19 Great Deals out of 549 listings starting at $2,800
2006 Pontiac Grand Prix For Sale
25 Great Deals out of 615 listings starting at $1,999
2005 Pontiac Grand Prix For Sale
22 Great Deals out of 489 listings starting at $999
2004 Pontiac Grand Prix For Sale
20 Great Deals out of 656 listings starting at $1,500