Are the fans running on low or high ?
Circuit/System Description
The engine control module (ECM) commands the fans ON in either high speed or low speed, depending on cooling requirements. In low speed, both fans are turned ON at a reduced speed. High speed has both fans turned ON at full speed.
In low speed operation, the ECM applies ground to the coil side of the fan low relay. This energizes the coil and applies voltage directly to the left cooling fan through the switch side of the fan low relay, which is fed by the fan 1 fuse. The right fan is connected in series to the left fan through the de-energized fan control relay so that both operate at low speed.
In high speed operation, the ECM applies a ground to the coil side of the fan low relay, the fan control relay , and the fan high relay. On the fan high relay, the energized coil closes the switch side of the relay and applies voltage directly to the right cooling fan through the switch side of the relay, which is fed by the fan 2 fuse. At the same time, the ECM energizes fan control relay pulling the switch side over, providing a direct path to ground for the left cooling fan, which has voltage applied through the energized fan low relay. In high speed mode, the fans are operated as a parallel circuit with full voltage applied to each.
You should have it hooked up to a scan tool that can read engine sensor data parameters . Check for DTC'S - diagnostic trouble codes etc...
Circuit/System Verification
Your best bet is to take it to a ASE certified repair shop !
SOURCE: 99 chevy malibu
Your fan motor might be fried... and check your coolant, they have a tool which measures its ability to do its job. you might need a radiator flush but start small... THe tool to make sure you anti-Freeze is good is very cheap. By one and test it (it tells you how to test it) then check your fuzes for your Radiator fans in your owners manual. if that is good take your fans off and have them tested. you need to get your fans working again even if you need to by new. And see if your car needs a coolant flush, ( a true flush not a drain and fill
SOURCE: cooling fans on 2001 chevy malibu will not come on unless ac on
the relays control circuit is grounded by ECM (computer) . to check this make sure the is hot enough for the fans to be commanded on by computer and check to see if you have voltage at relay and it has ground from computer . you may need ECM.
good luck
SOURCE: electric fans run all the time
The radiator and A/C condenser fans are triggered by high coolant temperature or when the A/C is turned on. Check to see if you have a relay sticking closed. The (ECT) engine coolant temp. sensor could also be defective telling the computer that he engine is too hot all the time. If you can locate the relay it's much like the others and you can swap it with a good one for a simple function check.
SOURCE: engine hot ac turned off on 2008 chevy silverado.
My truck is doing the same thing, also the gas gage is no longer correct, it was all due to a wiring harness i believe, covered by warrenty
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