Car will not start- will crank- anti-theft light flashes - turn switch to on for 10 min. when light stops flashing - turn switch to off - then it will start. Changed to a new switch - worked or started for a few days now won't start.

try to start the car then leave the ignition on for exactly 10 minutes then turn the key off(anti theft will stop flashing). and try to start it again..... might take three tries

Here are two methods to reset the anti-theft system on 2007 Chevy Malibu:
1st method
1. Put the ignition in on position, let it breathe for 10 minutes, and remove it when the anti-theft system light stops blinking.
2. Crank up the engine; it should now start
2nd method
• While outside the car, press and hold the lock and unlock button together
• Let go when the car honks and the lights flash
• Put the key in the ignition and rotate to the ON position, and leave there for 30 seconds
• Switch on the car, and the anti-theft system would have reset

If the anti-theft light is flashing, turn the key to the On position and leave it there until the light stops flashing. Turn the key off, then try to start the car. The Anti-Theft system can get tripped for no reason and cause this exact problem.

You probably can't.
If the anti-theft module is in the cluster, you would need the correct key chip for the car the cluster came out of.
You might be able to bypass the passkey system by running a wire to the fuel pump relay and other components.
You may need a shop manual to find the circuits.

put key in trun to on do not start or try to start just trun on. wait 10 to 20 min.s with key on this should reset the theft system.after you wait turn key off then try to start.

if the theft light is was flashing on you, put the key in the ignition and turn all the way until the instrument cluster lights up, just don't start the car. leave it like that for aprox. 10 min. or until light goes out. when that happens, turn of(don't take out keys) and try to start car. hope it works.

The antitheft will need reprogrammed when you are done. But it is fairly easy to do. Just leave the key in the run position until the security light stops flashing. (10 min).

I just had this on my car too. Turn the key to "on" without starting the engine. Look at the display and see if the Anit-Theft light is blinking. If it is, you need to keep your key in the on position for about 15 minutes until the light stops blinking. Start the car when the light starts blinking.

ok you need to re-learn your passlock. to do this. turn the key all the way to start and leave it on. you will then see the passlock light flashing. let it sit for 10 mins. or until the light stops flashing. then turn the key off and take it out for 30 secs. repeat this 2 more times. after the last 10 min cycle when the light stops flashing. take the key out for at least 1 min. now try to crank the vehc. that should solve your problem. have a great day!