have 89 lincoln contl.sigture seires when light is and heat are on battery drain is and charge system light comes on,but in daytime you can not use window is or radio samething happens check and tighted all cables altertor good what can it be

Defective Regulator, have the Alternator replaced. The regulator is inside the Alternator.

either the battery is a bout to give out or the alternator is about to give out.to test if the alternator is going bad while the car is running disconnect the positive battery connector remove it and if the car turns off change your alternator and if the car stays on after you unplug the positive connector is your battery simple test .

yea, new alternator is in need there, also check the battery that might need replacement if its old as well.

you may have a short in the circuitry and it could be something that is not even related to the lights. somewhere some wires have crossed causing strange things to happen look for something that does not work and check the wiring for that.