03 impala coolant fan not kicking on...

[JL KINGw7]

i have a 03 impala 3400 model the cars coolant fans will not kick on when the car get to temp i've checked the fuses coolant temp sens and replaced the radiator cap fluid is fine...could the thermostat have anything to do with it?fans were replaced too about 3 months ago pls..any info will great..

[Iflylow]

Check the fans connector for corrosion, correct attachment.
If it is warm enough (ought to be in FL) turn on the air conditioning, at least one fan should run all the time the a/c is on.
Thermostat shouldn't be an issue if the car is reaching normal operating temp (180-220 F).
Loss of data from the coolant temp sensor makes the fans run all the time, so that isn't it.
The fans don't normally run until the temp is over 230 F, I think. Anyone know the exact temp?

[JL KINGw7]

see thats what i thought when i cut the a/c switch on the low speed fans kick on and the car does not overheat but thats were im stumped is there anything else im missing...relays are fine too.

[mp1642]

Unfortunately the Impala is victim to faulty Body Control Modules ( BCM ), that can fail or intermit. fail, causing erratic electrical problems including the engine fan(s) control.
1. if available command the fan with a scanner ( Tech 2, Snap On Modus, Solus ect. )
2. If you can command the fans as described in #1, then check for a signal from the BCM commanding the fans

Let us know your progress or further questions. I hope that helps

[j cAT]

Originally Posted by JL KINGw7

i have a 03 impala 3400 model the cars coolant fans will not kick on when the car get to temp i've checked the fuses coolant temp sens and replaced the radiator cap fluid is fine...could the thermostat have anything to do with it?fans were replaced too about 3 months ago pls..any info will great..

when the engine gets to proper operating temp the fans do not come on...only when the engine temp rises to about 230 deg f will the fans come on...

IF THE FANS COME ON AT NORMAL OPERATING TEMPS THE FAN MOTORS WOULD NOT LAST VERY LONG !

If it were 90 plus deg F air temp , and the a/c is on , both fans should come on if you have the proper amount of refrigerent in your ac system...this is because the both fans will be commanded on ,with the high ac refrigerent presures..when the temp drops or the refrigerent pressures drop only one fan comes on with the ac on....