Q: 2007 chevy malibu will not start checked fuses and relays, replaced battery starter and ignition switch

If you replaced the starter, I presume you were not getting any cranking at all. With a fully charged battery in good condition, and the immobilizer (security) system off - check to be sure the immobilizer is not activated - if the starter motor does not operate at that point, there are only two possibilities: 1) either there is no power to the starter motor/solenoid, or an excessive voltage drop, hence the entire starter circuit would have to be diagnosed; or 2) there is power but the starter/solenoid itself is bad and that includes intermittent operation which does happen. Of course, you have a new starter which rules out this second possibility. If you desire that a specialist from YourMechanic diagnose the starter circuit, and get your car running, please request a no start diagnostic. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.