Loss of battery charge overnight.

[CRUISER8]

Been searching for the root cause of the wives car overnight loss of battery charge. Have checked most fuses for any amp draw while ignition is off with no luck. Alternator diodes check out good and will be checking starter solenoid and starter for possible amp draw while ignition is off. In the process of trouble shooting I discovered a purple wire under the hood that has been clipped off and next to it a gray wire leading to a small glass tube with a ball of mercury in it attached to the underside of the hood. I am curious if this bulb is an aftermarket add-on and causing my battery drain. Inside the car and coming through the firewall next and leading under the dash next the fuse panel. What I need is a wiring schematic of power sources from the ignition switch to the fuse panels. 1996 Buick LeSabre with the usual accessories and a 3.8 V-6. Any help on this would be appreciated. Thanks

 

[CRUISER8]

I have located a after market alarm or anti/theft device under the dash on the driver side of the car. Appears that it has been spliced into the ignition switch wires and has an array of wires leading to the after market box. It's a cobbled up mess of electrical tape and and wiring leading to the box. Curious if all I have to do is remove the leads from the ignition switch wires that are spliced in to remove the after market box from the system. Dang thing is spliced into the red, yellow, and pink wires out of ignition switch.

 

[Spriteman]

Let me know if this helps - if not I can maybe find another one -