Just replaced a cracked radiator in my 99 C70 and the cooling fan was working perfectly before the install, but is not turning on now. Tested the relay and fan, they are both good. Turned on AC and still nothing. Sender bad??? Any ideas???

Thanks,
Mark

 

The ect might be messed up but on the other hand there is 2 circuits for the cooling fan.
The A/C is a different circuit from the coolant temp sensor. Double check all connections.

 

Is the ect the same as the ecm? and I tried all the connections onthe relay and the fan connections....what else could it be?

 

The ECT is the electronic coolant temp sensor located in the thermostat housing. Follow the upper hose to the motor. Then look under where the hose attaches there is a sensor that is the ECT.

But if that is bad then the A/C should still turn it on.

That's why I said to double check all connections. Make sure none of the wires backed out of the plugs.