went to start the car and the security light was on

Hi,

I need you to try something. Turn the key to the run position and wait for approximately 10 minutes to see if the light turns off. If it does, see if it then will start.

If that works, perform the attached reset procedure. It will take 30 minutes but should take care of the issue.

Let me know if this helps or if you have other questions.

Take care,

Joe

See pic below.

This security light doesn't go off after 10 minutes, not 15.

Okay, at the end of the left instrument panel is a fuse box. Pic 3 shows four fuses I need you to check. Additionally, make sure there is power to and from the fuses.

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Also, pics 1 and 2 are the wiring schematic for the anti-theft system. I'm providing them for a reference.

Let me know what you find.

Joe

See pics below.

They are not burned out, the fuses.

Hi,

Are you getting power to and from them? The fuse could be good, and failure happened before the fuse.

If there is power and the fuses are good, go to the body control module and see if it is receiving power from the fuses you checked. Wire color is provided in the schematic.

Let me know.

Joe

So, I could do that with a multimeter? I will have to go buy one tomorrow.

Hi,

You could use a multimeter or even a test light. I'm suggesting this because the problem could be before the fuse. Just disconnecting the negative terminal shouldn't have caused this to fail. I'm thinking there may have been a power surge and it caused a fuse (upstream) to fail.

Let me know.

Joe

There was also a wire for an amp (radio) hooked to the negative cable. It was there when she bought the car, maybe the source of the parasitic drain?
Anyway, I'll buy equipment later today and get back with you.

Hi,

As far as the ground, if it was not connected to anything, it is unlikely related to a parasitic power draw unless it was in contact with a component that could use it to complete a circuit.

Let me know what you find.

Joe

If I've done this correctly here's the readings I got:
PCM/BCM/cluster: with key on, without key on both 0
BCM; with key on without key on 0
lh/htd/st/BCM: with key on, without key on 0
clstr/BCM: with key on .04, without key on 0

I'd have to trace that ground wire...

Hi,

Are they all not working (no power)? If that is the case, go to the under-hood fuse box and locate the left instrument panel fuse box fuse (60 amp). That fuse is what powers the interior fuse box and components you are checking.

I attached a pic below of the fuse location.

Let me know what you find.

Joe

See pic below.

All things seem to be working, just not able to start the car, security. Going to have to study a bit to make sure I'm using that multimeter correctly; I've not used one before but want to learn. I had watched a couple of videos on it but maybe I didn't get it right. I will study.
Thank you very much for your continued help. :-)

Okay, let me know what you find. Also, if there is no power, check the 60 amp fuse I recommended.

Also, let me know if you have questions related to the meter. Here is a link you may find helpful:

https://www.2carpros.com/articles/how-to-use-a-voltmeter

Take care,

Joe

Thank you. I will keep you informed until this project has reached its conclusion.