Hello,
I new to this forum. So after taking the 1981 monte carlo to two different repair shops and no answer for battery drain I decided to join. I have a 81 monte carlo with a 350 V8. It has a new battery, new alternator, and new starter. The battery is drained overnight. Is their any electrical schematics for the charging system or what could be the issue.

 

Parasitic drains can be a real challenge to locate. It could be anything from a bad switch to a frayed wire making contact with the body somewhere. Was any work done to the vehicle just before the problem began? If so, that would be the first circuit I'd look at. Best bet for diagrams would be to purchase a repair manual for the vehicle. The easiest way I have found to pinpoint a parasitic drain is to pull fuses one by one over a period of time until you pull one that prevents the battery from draining. That will be the circuit you need to check for the problem. I'd start with the ignition, lighting, then move onto the smaller circuits.

 

I had the car about a month before I decided to replace the starter. I had a mechanic replace the starter and once he was under the car he said he noticed that the previous owner had the starter grounded incorrectly. He said he put it in the correct spot. Ever since then the car has not been able to keep a charge. I replaced the ignition switch. two shops have taken a look at the car but nobody can figure whats going on. I am thinking my mechanic rigged something so he can continue to take my money but he is not answering my phone calls so i can ask him whats the deal. Is there away you can rig a car to drain battery while engine is shut off? Also is there away around the issue I am having like battery switch or kill switch?

 

You could put a quick disconnect at the battery, but imo you'd just be applying a band-aid rather than solving the problem. If the battery didn't drain prior to having the starter replaced that would be the first place I'd look. The ground for the starter is established through the body of it, so I'm a little confused about your mechanic saying it wasn't grounded properly. If checking electrical circuits is something you are not experienced in then I'd find a local shop that specializes in eletrical and let them have a look at the car.