2002 Chevy Impala 3.4L coolant fans not working.

Coolant temperature sensor. Is your temp guage going higher than normal?

Yes it is

Check engine light on? If so, have it read and go from there

I would change the thermostat also as hot coolant might be stuck inside engine and cold on outside not being able to circulate. Stuck closed

Nope no check engine light. Thermostat and water pump have been changed and bled.

Like I said the problem is that the fan doesn't turn on unless I turn on the AC. Then both fans work. If I don't turn on the AC then the fans won't turn on.

Coolant temperature sensor

Also check the fan relay and any fuses.

Ok I will check those and let you know how it turns out.

Ok so I changed the coolant temperature sensor and no luck. I switched all relays around except for one which is fan relay 2 being that it's the only one to have that size relay. I'll change it and see what happens.

I've been told there's also another sensor. Coolant level sensor on the radiator which can also cause the fans not to work. I'll try to change that and we'll see what happens.

Are you getting power to the slots in the fuse box that you say have good fuses and relays? Do you have corrosion or wire issues under fuse box to the components? Green crusties?

Thanks, It was the coolant level sensor on the radiator.

Yep thanks for the update