Efans wont kick on an low coolant

[TolowSilverado]

I have a 2005 silverado my efans wont kick on i checked my relays they are all good i changed my temperature sensor still wont kick on but i give them direct power an they kick on i the whole plug is not getting power my low coolant light comes on but these dont come with the reservoir sensor what could be the problem its getting me frustrated please help 

[Jsdirt]

You need to find out what you're missing - an input, or the output. The temp sensor is one input. A bi-directional scan tool will be a HUGE help. See if you can command the fans on - if so, it's more than likely an input issue. Just because a sensor is new doesn't mean it's good, and just because a sensor isn't working, doesn't mean it's bad. You need to find out what is working and what isn't. The computer controls all of this based on inputs - without the correct inputs, the fans will never see power.

[Fullfrontal187]

On 9/24/2021 at 2:31 PM, TolowSilverado said:

I have a 2005 silverado my efans wont kick on i checked my relays they are all good i changed my temperature sensor still wont kick on but i give them direct power an they kick on i the whole plug is not getting power my low coolant light comes on but these dont come with the reservoir sensor what could be the problem its getting me frustrated please help 

Hi. It is possible to pay good money for a defective engine coolant temperature sensor. For those of us that do not have a bidirectional communicating scan tool you can narrow the issue down by disconnecting the clip from your ECT while your engine is running. If your fan or fans turn on high speed like they should without any sensor your fan control relays and wires involved need to be thoroughly checked. Try clearing any trouble codes stored in your computer and check your a.c. wiring too. I cannot answer specific without knowing the vin or if it is a drive by wire? Or drive by cable. Good luck you're halfway there.