Parasitic battery drain

Hi: I recently had my battery replaced and it died three months later. I was told that this could be the result of a battery drain because the voltage was extremely low, and yet, the battery subsequently charged okay. I did notice that when I cranked the ignition, there was a motor sound coming from the CD player but there was no CD in the slot.

At least a year before this battery replacement, my left turn signal switch stopped working and it would not turn the signal off without me physically moving the arm back to neutral. The volume control knob stopped working as well.

Now, after this battery replacement, the car door lock switch will not lock the door. I have to use the key. (My keyless entry device has been dead for years.) The left headlight is dim. The dome light doesn't come on when it should. When the driver side door is ajar, the chime sounds on and off, randomly, even when the key is out of the ignition but if I leave my headlights on, the chime doesn't sound. Everything is miscuing.

I have a cracked dash which now causes vibration on the passenger side. The rubber trim around the door window leaks into the cab so when it rains, there's more water inside the cab then outside. This causes condensation on the instrument panel.

The technicians could not find the drain source because it's intermittent.

I think that part of the problem might be a bad column switch or relay or corroded something but I can't take everything apart.

At this point, I need to know where I can take this car to have a thorough electrical diagnostic test performed. From everything that I've read, this doesn't sound like anything that I can perform. Any information or recommendation that you may provide would be greatly appreciated.

Also, the starter was replaced in 2013 and I was assured that the alternator is working. I do notice that these problems arise after a heavy rain and when I park my car on an upward incline. When I turn the key and apply pressure to the brake, it locks and I can't depress it. The car is really old and porous but this is a new kind of bad.

Thanks for all your help.