Hi,
I am having issues with my stock security system on my 2000 blazer. I have searched all over the Internet and have not been able to find an answer to my specific issue. When I get into the vehicle I insert the key, once I turn the key forward to start the car the security system begins to go off immediately and will not allow the vehicle to start at all. it does not attempt to turn over. i have tried purchasing a brand new battery, using the internal locks, locking and unlocking from the outside using the both the key and key multiple times. I have also tried disconnecting one and both leads to the battery for an extended period of time. I have not installed any aftermarket parts or replaced any OEM parts. This issue started out of nowhere and I have been down a vehicle for the last couple weeks. I had a similar problem with this vehicle when I first picked it up form my parents. it had issues starting due to the security system, but it began working again, I do not know what was done to make it work the first time.

Any help would be apreciated, I would love to completly disable the security if at all possible so I never have to deal with this issue again.

Thanks,

-Nick

 

Possibly a worn key. Do you have another key to test?

 

Just tried my second key to be sure... same issue.

Thanks for the speedy reply.

-Nick

 

My understanding from reading here is the ignition switch can cause problems with the passlock system. I am sure there must be some treads here discussing it. It is mentioned as a common problem on 2nd generation Blazers in the how to replaced your ignition switch thread in this link.

https://blazerforum.com/forum/articl...-thread-26553/

Blazeme

 

I'm not sure if it applys to your year blazer, but I had a 97 doing the exact same thing after the battery would die, The way I personally was able to get it to start was by putting the key in the ignition, turning it to the run position, taking the battery out waiting 10-15 mins and then hooking the battery back up with the key still on the run position. I'm not sure why it worked but it was the only way I could get my car to stop flashing the lights and let me start it.. let me know if it works for ya

 

Sounds like the switch built in to the drivers side key cylinder is worn out and not sending the signal to the body control module to disarm the factory security system. Try unlocking the passenger side door and see if that works. If that doesn't work, The BCM is located to the right of the accelerator pedal below the radio. The plugs on the BCM face towards the drivers side. There is a smaller purple blug on the top that has a light green wire. This wire disarms the factory security system. Send a ground signal to this wire and it will disarm it. Hope this helps.

 

This does not sound like a passlock issue, but really like an ignition switch contact issue. The passlock system does not prevent the engine from turning over, it will just cut the injectors a few seconds after the engine starts. Since the engine isn't even turning over, I would suspect the contacts in the ignition switch (see link in my signature below) provided everything in the cranking circuit checks out ok.

 

I agree with Swartlkk. Gf's Malibu did the same thing. Crank it and it starts for a second then dies like its out of gas. Very confusing at first. But it will crank until the cows come home. Just wont fire the injectors.

I seem to remember having a car that had a loose or corroded battery cable. It wouldnt crank and the low voltage created by the bad connection set the security system off.

My gut says its something simple.
Good luck!

 

@ Jakethegreat440 - I tried your suggestion of turning the key to run and then disconecting the battery. I disconnected the negative wire and left it for at least fifteen minutes. The alarm continued to go off once I tried starting the vehicle again (the lights actually started flashing right as i connected the battery again).

@ Blazed&Confused - tried unlocking from the passenger side... No luck there. Where would you suggest I pull a ground wire form to connect to the light green security wire? Anyone else have an opinion on trying this to fix the problem?

@ kristoph30 - My vehicle will not crank. Not even for a split second will it crank or run.

@ swartlkk - If i disable the security as mentioned by Blazed&Confused, would I be able to avoid replacing ignition switch.

Just a few more notes: The security light does flash when entering the vehicle, the alarm begins to sound as soon as the key is moved into the run position (do not need to actually turn it all the way forward to start position), and my battery terminals are clean.

Thanks everyone so far for your suggestions, it is much appreciate.

-Nick

 

Hm that was all the input I had sorry, hope you get it worked out though!