problem with cooling fans not coming on

25

Asked by Jul 18, 2007 at 12:13 PM about the 2003 Chevrolet Impala Base

Question type: Maintenance & Repair

cooling fans don't come on,when driving,replaced fans,replaced water pump.and temp sensor 3 times,still not working... but if I remove 1 wire from temp sensor fans come on but temp gauge show zero..Now air conitioning won't work check all fuses and relays all good! but can remove relay from air condition compressor and jump it and air works! what show I check  or do now...

22 Answers

44,205

Sounds like the relay for the cooling fans is bad. This is a common problem. Removing the wire from the temp sensor puts the fans into stay-alive mode, and they run constantly as you found out. Have the relay replaced and you should be fine. As far as the AC, it is most likely related to your cooling fan problem. In order not to increase engine heat, the AC is determining that it has to stay off to keep the engine cool. Solve Job 1 and you should have Job 2 in the bag.

39 of 39 people found this helpful.
280

bull ...these cars have problem with bcm ,,,and ecm's with one car the ac compresser comes with ac off ...and over heats cooling fans will not come on !!!!!

28 of 28 people found this helpful.
200

Aflores1955, what did you finally do to fix this issue? Was it the cooling fan relay? I have the exact same issue on my Silverado, and everything you described to try, I tried and it behaves just like your car does. If you can let me know.

20 of 20 people found this helpful.
300

I too am having same issue. I have replaced all three relays, ECT, fan assy (due to one fan burnt out), had BCM and PCM checked (both good), all wiring checks good, all signals at correct places but still no fan activity except for 10 seconds every couple of minutes.

29 of 29 people found this helpful.
230

I replied to "Fan Problems" on this page you can read what I did for my 2000 imp, I replaced nothing but just cleaned contact points on fuses and relays(note that they all checked out good beforehand). My fans hadn't worked at all for two years, then voila! Might work for you.

23 of 23 people found this helpful.
340

02 impala, fan fuse kept burning out. ac fan still working but cooling fan fuse kept burning up as soon the fan start up.

34 of 34 people found this helpful.
160

#1 fan fuse blows when I turn the ac on in 2001 Monte Carlo SS

16 of 16 people found this helpful.
70

Try removing all fan relay's coat them with dielectric grease, plug them back in and this should work.

7 of 7 people found this helpful.
40

From were you replace cooling temperature sensor??if its autozone or o reilly u are having a big headache if my opinion is good 100% it would work if you buy it from the dealer cost around 40 dollars but it works

4 of 4 people found this helpful.
60

I have a 2000 malibu Ok im having almost the same problem my ac comes on when I start the car blows hot air.. for 3 min n but my fans still dont come on and slowly my ac cuts off...I dont have relay 10 or 6 would that stop it from wrking

6 of 6 people found this helpful.
20

Your a/c could possibly have a leak...check for freon leaks...maybe with soap bubbles ??? :)

2 of 2 people found this helpful.
200

09 impala fan came on high and stays on the whole time I'm driving but A/c don't work ... where is the relay switch so I can clean and electric grease and see if that works first

20 of 20 people found this helpful.
50

Make sure the PCM is well grounded. Fan and relay circuits route thru PCM to ground in order to operate. If not well grounded, fans won't operate. Check PCM ground wire- usually black/white wire- to make sure it is grounded to negative side of battery.

5 of 5 people found this helpful.
20

i agree with Kenair , check computer grounds

1 of 1 people found this helpful.
20

Had this same issue with my 04 impala and I tried all suggestions listed here with no luck. The fix was to purchase a used ECM from ebay and take to dealer and get it programed to you car. Fan Work now and also AC works.

2 of 2 people found this helpful.
20

kereynol, what did you do to end up fixing this issue? I haven't been able to fix my 2006 imp yet either with this issue.

2 of 2 people found this helpful.
90

I have a 2001 monte carlo, the fans don't come on until is almost in the red zone on the temp Guage, I've replaced the rad, water pump, thermostat, and both rad lines. Still over heats because the fans Dont turn on. How do u fix this?

8 of 8 people found this helpful.
20

First thing I'd look for is DTC's. Then check fan motors. You can "hotwire" them. If the motors work check the relays. If all that checks out, look up cooling fan relay control circuits on the web. Seems this basic problem has been happening for a few years. Also on GM's there are at least 5 inputs and 6 conditions that control operation of the cooling fans.

1 of 1 people found this helpful.
20

Almost forgot to tell you to bleed all the air from the cooling system.

20

I have 01 and my fans aren't commimg on and ac is not getting as cold as it should I have cleaned both boxes and different sensors and still nothing but I can take a piece of wire and put it from ground on battery to one connector on 2nd biggest relay on bottom and only one fan comes on so any help plz

1 of 1 people found this helpful.
20

If memory serves correctly; there are 5 or 6 different control inputs to the body control computer. The body computer switches the relay ground circuits on or off depending upon the various input values. If the relays are all functioning correctly, then you'll want to check the engine coolant temp sensor, the wiring from the relays to pcm, and the a/c charge level. For an '01 the freon charge should be about 2.2 lbs. Off the top I'd say that your problem sounds a lot like the a/c system needs a recharge.

20

Almost forgot to mention that the a/c low pressure side sensor also provides an input to the body pcm. Also if memory serves on this; low side pressure needs to be at least 40 PSI in order for the pressure switch to send the signal to pcm.

1 of 1 people found this helpful.

Your Answer

Impala

Looking for a Used Impala in your area?

CarGurus has 34,726 nationwide Impala listings starting at $1,250.

ZIP:

Chevrolet Impala Experts

  • #1
    Js08016
    Reputation
    1,850
  • #2
    Tom Demyan
    Reputation
    1,760
  • #3
    Danny Wang
    Reputation
    1,680
View All

Related Models For Sale

Used Chevrolet Malibu
1,258 Great Deals out of 77,876 listings starting at $1,500
Used Chevrolet Camaro
419 Great Deals out of 31,911 listings starting at $2,395
Used Honda Accord
1,046 Great Deals out of 63,026 listings starting at $999
Used Nissan Maxima
323 Great Deals out of 23,728 listings starting at $1,550
Used Ford Mustang
770 Great Deals out of 42,663 listings starting at $1,300
Used Nissan Altima
1,120 Great Deals out of 74,981 listings starting at $999
Used Toyota Camry
1,098 Great Deals out of 72,559 listings starting at $1,000
Used Chevrolet Tahoe
642 Great Deals out of 36,955 listings starting at $1,800
Used Chevrolet Silverado 1500
2,129 Great Deals out of 183,036 listings starting at $1,898
Used Chevrolet Monte Carlo
14 Great Deals out of 1,353 listings starting at $995

Used Cars For Sale

2018 Chevrolet Impala For Sale
5,618 listings starting at $23,206
2017 Chevrolet Impala For Sale
81 Great Deals out of 10,384 listings starting at $16,000
2016 Chevrolet Impala For Sale
38 Great Deals out of 1,549 listings starting at $13,898
2015 Chevrolet Impala For Sale
25 Great Deals out of 1,360 listings starting at $10,750
2014 Chevrolet Impala For Sale
85 Great Deals out of 2,588 listings starting at $9,700

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.