I am experiencing alot of electrical issues on my 65 cutlass. Here's my scenario.
engine runs fine, headlights and high beams work fine, tail lights work.
Passenger side blinkers work, driver side don't. Passenger side brake light works, driver side doesn't. When lights are on blinkers don't work at all. Horn doesn't work. Also car has a slow draw which will kill the battery if it sits for more than a few days. I usually disconnect the battery when not in use because I just installed a new battery and don't want to ruin it. I am going to get the alternator tested but it is relatively new only a few years old so I believe it is working and chsrging the batterry when in use. Is there a way I can test the alternator in the car?
also, the convertible top only works when it wants. I feel like the only solution is to rewire the whole friggin car but would rather not for obvious reasons.
well anyway where should I start to figure out why I am having these issues. Want to grab volt meter and start identifying why I'm having these problems but feel a bit overwhelmed.

 

sounds like ground issues . I would start there at trunk and front bumper area...

 

Do not just jump in and re-wire the car. Learn how to read the wire diagram and use your voltmeter to tackle one problem at a time. Driver brake light and turn are related, if you fix brake light trouble likely will fix turn signal. Top trouble is likely switch or circuit breaker. A 12 volt test light can be easier and faster to use then a voltmeter.
Do a search on battery draining for ways to troubleshoot that problem with a meter or light.

 

Troubleshoot each problem individually.

 

I would start with the current draw. You will probably fix other issues in the process.
If the draw is big enough to create a spark on the battery top, pull the fuses one at a time and see where the spark goes away. If it does not go away, the current draw is in some circuit that is connected directly to the battery without a fuse, like the horn, or charging system. You'll need your wiring diagram to do it properly.
IMHO, you could replace the entire wiring harness, and still have issues, because many problems are not in the wiring, but in the components at the ends of the wires.

 

Let's start with basic troubleshooting. First, the rear turn signals and brake lights use the same filament in the bulb, so that is likely a common problem in your car. Second, since turn signals on one side work, obviously you're good at least up to the switch. I ASSUME you've verified that the rear bulbs are good?