A couple other things - although the fact it does not come on with AC is one sign the fan is bad.

1 Unplug the coolant temp sensor with car running. It should cause the fan to run.

2. Unlock the cluster sub-menu (read up on it) and enable test 7 to show coolant temps. Once temps hit 100C at idle the fan should come on. Don't let it go over 100C


I just replaced my aux fan in my '05 3.0..it was dead which I confirmed with INPA.

I went with the TYC brand (Taiwan) off amazon. Decent reviews.