2003 Ford Thunderbird overheating

First look at the cooling fins on the radiator to see if they're corroded away or they crumble real easily. If they're okay you might want to have your mechanic do a "sniffer" test at the radiator to check for a leaking cylinder head gasket.

In some cases removing the thermostat can cause overheating because the hot coolant circulates too fast and doesn't stay in the radiator long enough to give up its heat.