Hi,
There are a few possibilities, and you will have to do some testing.
First, test the fuses (under the hood) that supply power to the relays that control the fans. Next make sure that the engine is getting warm enough to actually turn the fans on. Then, also see that the wiring is all connected so that the fans get voltage at the appropriate time. Lastly, it could be the fans themselves, but if both are not working, then it is probably something else.
I have provided a link that shows how the system works, which might be helpful.
Good Luck
Check coolant level Cooling fan working? Dirt or clogged radiator? Defective radiator cap?
Use a flared end wrench or crows foot to loosen.
The drain plug on the 2003 Chevy Venture is located on the bottom edge of the radiator. It is on the side facing the engine.
The radiator drain plug on a 2004 Chevy Venture is located at the bottom, left side of the radiator. It allows for the coolant to be quickly drained during maintenance.
yes
The thermostat on a 2004 Chevy Venture is changed by draining the radiator, removing the upper radiator hose, and unbolting the thermostat housing. The old thermostat and gasket can then be removed and replaced.
When the engine is cold, remove the radiator cap, top off with a 50/50 mix, and start the engine. This will allow air to escape from the radiator. It may also have bleeder valves located high on the cooling system. The location will be listed in your owner's manual.
Blown head gasket.
Try to determine the substance: i.e. Transmission fluid (bad radiator) Engine oil (bad head gasket) Try flushing the cooling system and tracking other fluid levels
I've got a better question, why is this question in the Chevy venture forum ?
The heater core is part of the heating and cooling system, and it is the circulation of the radiator fluid that supplies heat to the core. The water pump on the car is what is responsible for the circulation of radiator fluid.
Blown head gasket.