My car wont crank all the lights com on but the light in the car just wont crank? is it in security lock if so please help??

This may be related to the antitheft security system. The system is known for turning off the starter and/or injectors when it fails. When it's the security locked out starter, you won't even hear a click when you turn the key. Is there a light on the dash that says SECURITY or a picture of a car with a lock through it? This is a common problem worth looking into. http://www.diy-gm-security.com/

check that it has power at the coil ,crank sensor,etc. with a test light when cranking it over.

The security, antitheft or lock picture/icon is a visual indication that something in the car's antitheft system is failing. In most GM cars and trucks there is a hidden system that most people are unaware even exists. From the moment you put your key in the ignition, there begins a constant line of communication between your key's security chip or transponder, to the ignition's lock cylinder, and then to the car's TDM (Theft Deterrent Module). These 3 parts are in CONSTANT communication. If the key is in the ignition, then these parts are sending signals to each other. The security light illuminates when that signal gets broken, even just for a second. When the signal breaks, the car misinterprets this as an attempt at theft and goes into antitheft mode. The car thinks its being stolen or hotwired because it is not getting that signal from YOUR specific key. This is why the security light turns on and shuts down your vehicle. This link explains it pretty well.
http://vatspasslockpasskeysecurityhelp.yolasite.com/

Depending on the make model and year, did you have a key cut to match the new lock cylinder and the old key chip ?

is the car in park also try neutral. is the security light flashing. get out lock all doors open car with key in the laock on the door and retry

try locking all the doors with the key .if that wont work.turn the ignition multible times on off ect.if that wont work disconect the battery.reconect and try it .the alarm is cuting youre fuel off good luck hope this helps you

The security light is a visual indication that something in the car's antitheft system is failing. In most GM cars and trucks there is a hidden system that most people are unaware even exists. From the moment you put your key in the ignition, there begins a constant line of communication between your key's security chip or transponder, to the ignition's lock cylinder, and then to the car's TDM (Theft Deterrent Module). These 3 parts are in CONSTANT communication. If the key is in the ignition, then these parts are sending signals to each other. The security light illuminates when that signal gets broken, even just for a second. When the signal breaks, the car misinterperates this as an attempt at theft and goes into antitheft mode. The car thinks its being stolen or hotwired because it is not getting that signal from YOUR specific key. This is why the security light turns on and shuts down your vehicle.
This link may help you find ways to bypass this or fix it yourself.
http://vatspasslockpasskeysecurityhelp.yolasite.com/

HAVE TO TAKE TO DEALERSHIP.SOUND LIKE THEFT DETERRENT SECURITY SYSTEM GOING BAD.COULD BE WORN IGNITION KEYS OR FAULT IN THEFT SECURITY MODULE.DEALERSHIP HAS TO USE A DIAGNOSTIC SCANNER TO FIND THE PROBLEM.

try locking and unlocking the drivers door with the key. [sometimes if you reach to un lock door through window it it sets off security]

how to get the security light off and to get my car off security so it will stay running