2000 buick lesabre wont turn

[MDDRJ74]

2000 Buick lesaber ,3.8Lt ,140,000mi

Hello, I have recently ran into a Problem that just bogels my mind. I drove my car all day mind you, went into a friends house and came back to the car (2000 Buick lesaber) and attempted to start it. It would not even turn over. No selections of the ignition switch would ingauge (key Pos 1,2,3). The lights illuminating the driver and Passenger door window and lock buttons are constantly on (have to unplug the battery) and the horn will stay ingauged if Pushed at all. The radio will turn itself all of the way u or down when battery is plug back in but, no power to it other than the tiny security light(on the head unit not dash). The power seats do move when battery is pluged in.I have no dash lights nothing other than the mentioned above.


WHAT I HAVE DONE:
Checked All grounds I know of.
Checked Battery
Checked fuses,fuse box ground studs
Removed ignition switch(Took it apart all contacts and wires are in pristine condition but what I observed was that the vehicle has the same problems with ignition switch removed so could that still be the problem?)
pass key 111 unit is installed factory but, the keys I have do not have chips in them, never have.(also security light it not blinking on dash)

Any and all suggestions and very welcome and thank all of you for taking your time to read and possibly help me out

[nomechanicatall]

Just read one on here the other day that might help. In the search bar for af (auto forums) type in 2000 lesabre strange electrical problems. He talks about the dealer finding the bcm or some module under the back seat bad. Good luck

[MDDRJ74]

ok i will check in to it now thank you very much

[MDDRJ74]

UPDATE:
I was tinkering with the vehicle this morning and found out that if I have the ABS box is unpluged. My horn issue seems to go away(It staying inguaged that is).

Also if someone could please tell me where the (PCM) is located. My haynes manual says "under the right side of the dash"
If someone could PLEASE be more specific of where there located I would be very grateful.

(REASON) To check the ground. I was reading something that was saying that a loose ground to the (PCM) would create a problem like that.

If anyone has any suggestions of something I could try anything and thank you again.

[MDDRJ74]

SOMEONE PLEASE HELP

[maxwedge]

Under r/s of dash. remove the panel below the glove box to access, but it does sound more like an issue with the bcm.

[MDDRJ74]

Thank you very much for your reply sir

Can you tell me where the (BCM) is located ? And also can I have it tested with it out of the car ? I will look for it again in the morning
-Untill tomorrow-
Thank's again

[maxwedge]

It must be tested with a scan tool, I believe you may have to get this to a qualified repair shop that has the proper diagnostic equipment.

[MDDRJ74]

Originally Posted by maxwedge

It must be tested with a scan tool, I believe you may have to get this to a qualified repair shop that has the proper diagnostic equipment.

Can you tell me where the BCM is located ? And can it be tested out of the car ?

[MDDRJ74]

Can someone Please tell me where the BCM is located ?