I just had the battery and alternator checked all were good. changed my spark plugs and now the battery isn't charging, I have no lights, radio, etc. on my 98 crown Victoria police interceptor

SOURCE: 2006 crown victoria - no heat

I would change the thermostat in the vehicle first and go from there. Hope this helps......Dan

SOURCE: 2003 Crown Victoria Police Interceptor

Assuming you have played with the child locks on the doors you may fnid that your particular car is missing the linkage from the interior door handle to the door lock. Apart from making up a rig yourself I would suggest going to a breakers yard or possibly your local Ford dealer

SOURCE: Headlights turn off while driving

Headlight module under the dash. It is the size of a box of crackers, not a small part.

SOURCE: Battery wont charge in my 1997 ford crown victoria

In the 1995 and later Crown Victoria's, there is a fuse in the fuseblock that controls the alternator's charging of the battery. If that fuse is blown, your car will drain the battery and cut off as you stated.
Check the fuse block under the hood and the one located on the left driver side above the hood pull.

SOURCE: cylinder 4 misfire on a 2000 crown victoria interceptor

first cylinder 4 is the last on the passenger side . first pull the coil out and check if there is water where the plug is. if there is take the water out and dry up the coil. if you find water you got a crack manifold or a bad intake manifold gasket. if there is no water replace the coil. good luck