My pontiac grand am will not turn over or nothing it was fine when i parked it this morning the security light stays on and keeps flashing

2 things I would check on this would be try cycling your hazard switch on and off a few times see if that changes the problem because your tsignals run through the hazard switch , if that changes what happens then replace hazard switch, next would be turn signal relay a bad relay can cause lights to stay on

PARK SWITCH ------ STARTER RELAY-------- IGNITION FUSE
TRY SHIFTING IN NUTRAL TO START
SEE IF GROUND WIRE TO MOTOR AND BODY AS GOOD CONTACT
DOES POWER TO SIGNAL WIRE OF SELENOIDE ON STARTER COMES LIVE
WHEN TURNING KEY TO START
IS THE SECURITY LIGHT FLASHING IN DASH

crank position sensor

when key on and engine off, does the security light flash constantly? if so its shutting down the fuel pump, it starts momentarily due to the computer priming the engine with fuel. how to reset, turn key to run position, leave it on touch nothing, takes 10-12 minutes, start watching light around 10 minutes. it will stop flashing... turn key off, then back on and start this will reset the security system. they are sensitive on this platform car it will happen again. good luck!

Mine side the same thing if ur security light is flashing keep it turned to the off position till it stops flashing then turn off and then crank

sounds like you need a new ignition switch the pass lock is screwing up common.

the security light will flash and disable the fuel injectors preventing the car from starting, if it thinks that it is being stolen. its easy to fix. set the parking brake to turn off the automatic headlights. next turn the key to the on position and wait ten minutes. the security light should stop flashing. then turn the key off and this will reset the security system. it should start immediatly afterwards.

Neutral safety switch may be going bad or is out of adjustment. Switch is on the transmission under the shift linkage ear where shift cable attaches. Loosen it and put car in reverse (not running) turn switch so that reverse lights come on. semi-tighten switch and check that it starts in both park and neutral. If not you need to change the switch.

The problem may be the security issue. Do you see a security light? Dust gets into the ignition tumbler and causes a bad contact with the sensor prompting a false security issue.

I had the same problem and thought it was a fuel pump issue, but after a $500 replacement ordeal, I later encountered the same issue again.

To resolve:
Insert the key and turn on ignition tumbler to ACC on (Position prior to engaging the starter)
Wait around ~15-20 minutes (The security light will change... I believe it will flash when the security reset...it's been a long time...sorry)
Afterward, turn the ignition tumbler and off
Your card should start there after

Tumbler maintain: Blow some compress air to prevent this incident from happening.

Hopefully this will resolve your issue without the need of spending any further $$$!

Dave

Mine did the EXACT same thing! After a lot of googling, I found that you need to put the key in and turn it to the 'ON' position and leave it there for about 10 minutes. The security light will eventually stop flashing and your car will be fine to start. CRAZY, I know! But it works! Thankfully Google saved me from spending MUCHO $$$ for parts I didn't need in the first place!