The engine may overheat at idle when the AC is on. A new, upgraded fan motor and resistor assembly should be installed.
2008 Ford Crown Victoria Problem Reports
Most Reported 2008 Ford Crown Victoria Problem Reports
The battery light may illuminate on the instrument panel because the alternator wire harness connector is damaged. A new connector kit is available and should be installed to correct this concern.
Transmission problems are common in this model, often as a result of a failed front pump. The pump loses its ability to create hydraulic pressure, which an automatic transmission needs to function. A sign of front pump failure can be a whine type noise.