I have 2005 malibu. Was working fine until today. It will not start. It turns and battery is good. Starter seems fine. What should I check.

probably where the remote start wire was taped into the starter wire got broken and now the key side isn't attached to starter anymore. Id check the starter relay and fuse before anything

This procedure usually works:
·Check the battery cable connections:
Make sure the positive cable, makes a good connection at the battery and at the starter. Make sure the negative cable makes a good ground connection at the battery and (preferably) at the engine.

·Check the battery the simple way, like this:
Turn on the headlights, then try to start the car.If the headlights do not dim or go out, then the battery is likely ok.

·Check the starter and solenoid:
If the wiring looks ok, then look at the starter solenoid for a good connection, and proper voltage at the starter(10 volts minimum while cranking).
If the starter spins and no crank, the problem is most likely the Solenoid's pinion gear is stuck.
Have someone hit (not too hard) the starter while you try to start the car. This usually works by dislodging a stuck pinion gear.
·Make a simple test of the alternator:
If you can, somehow get the engine running, measure the voltage at the battery. It should be at least 13.6 volts to properly charge the battery.

Possible causes are: 1. Loose or corroded battery cables. 2. Bad starter 3. Dead battery. Try tapping on the starter with a hammer while someone is holding the key in the start position. If it starts then replace the starter. Thanks

Maybe the anti theft system? Read about it on this link http://vatspasslockpasskeysecurityhelp.yolasite.com/

if the car does start without a jump start/boost, you probably have a bad starter motor. if you pump the gas when it doesn't start, the car will run rough when it starts until the extra fuel burns off.

bad or corroded ground wire to starter or lose starter ignition wire

Right side, down under. You say it turns over? if it turns over, the starter is working. Turning over and cranking are the same thing. It either CRANKS or it DOES NOT CRANK. or it CRANKS but wont RUN. Explain things in these terms so theres no confusion.

Okay, what you seem to be saying is the battery does not turn over the engine and the battery smokes when you jump it to start it. But the lights and radio and everything works except the car will not turn over by itself. The battery smokes because either the battery has a short in it, it smokes because the starter is dragging, and/or the jump wires are not hooked up red to red and black to black. You need to have the battery and starter checked. If the car runs take it to an autoparts place to test. Or if it won't run take out the battery have it tested and if it is good, then take out the starter to test it.

Sounds like your battery / starter may be dead. Do you get a clicking sound at all? A click will indicate a dead starter, a buzz indicates battery issues.

check the Ignition Starter Switch (tipical on tb)