1993 pontiac bonneville se security light is blinking when u turn switch on and the car will not start at all....

Relay possibly

https://www.google.com/search?q=1994+bonneville+se+fuse+headlights+not+working

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That is a know issue with that model car.
If I remember correctly you have to put the key in the ignition and turn the car on (Don't Start it) Just leave it On for about 10 min. the light should go out . Then turn it off and then start the car.
Hope that Helps.

the anti-theft system has activated and will have to be reset. I think the procedure is turn key on for 3 minutes then off for 10 seconds then on until the security light flashes on the dash then turn key off. if should start.

Try the connection's to the battery, they might be loose, also check the wire from the starter to the battery . One more thing I can think of, is the factory installed security system. Try unlocking the driver side door with your keys, and hold it forward for about 10 seconds.

What you need to do there is to turn the ignition switch on and off three times, leaving it on the third time. Leave it on for about fifteen or twenty minutes and the light should become steady. then you can start the engine. (I usually put a jumper battery on it to make sure it does not knock down the battery too far) If that fails to work, then the problem likely is in the switch or the security module.

Hi, check.........I need to know which fuse runs the cooling... on this forum thread. Its not a fuse if the fan turns but could be fan relay. Unplug the coolant temp sensor lovated just below the thermostat houing and see if the fans come on. If they do, it might be the coolant sensor that is bad.

No,check for spark first. The security code comes off the key itself & never needs servicing. If no spark,there's a load of things to check,but start with the fuses, then engine codes. Should narrow it down a bit.

when u see the security light blinking and it wont start u simply turn the switch on and leave it on till the security light stops blinking then turn the switch off and start the car up

your key reader is not reading the chip in your key you can either replace the ignition switch cost about 250 dollars parts and labor or i can tell you how to bypass it for less than 20 bucks in premium chat hope this helps
thanks wes

you have a bad key or bad security relay