When I use the turn signal, left or right it

Turn Signal Lamps
The body control module (BCM) is responsible for controlling the turn signals and hazard lamps. When the turn signal switch is placed in either the left turn or right turn position, the BCM receives a signal from the turn signal switch. The BCM then sends an on-off voltage signal to either the left or right turn signals and their instrument panel cluster (IPC) indicator. When the hazard switch is pressed, the BCM receives a signal from the hazard switch. The BCM then will send an on-off voltage signal to all the turn signal lamps. All the turn signal lamps will flash including both IPC turn signal indicators.
Stop Lamps
The body control module (BCM) is responsible for controlling the stop lamps. When the driver presses the brake pedal, the BCM will receive a signal from the brake pedal position sensor. The BCM then supplies battery positive voltage to both left and right stop lamp assemblies and to the center high mounted stop lamp (CHMSL). The stop lamps are grounded at G401 and G403. The CHMSL is grounded at G302.

Something is messing with the BCM'S mind ,bad input data ,shorted circuit etc... Hooking up a professional type scan tool is needed to read BCM DTC'S - diagnostic trouble codes an view live data to the BCM .

DTC B3948 02: Left Front Turn Signal Circuit Short to Ground
DTC B3948 05: Left Front Turn Signal Circuit Short to Battery or Open
DTC B3949 02: Right Front Turn Signal Circuit Short to Ground
DTC B3949 05: Right Front Turn Signal Circuit Short to Battery or Open

DTC B3950 02: Left Rear Turn Signal Circuit Short to Ground
DTC B3950 05: Left Rear Turn Signal Circuit Short to Battery or Open
DTC B3951 02: Right Rear Turn Signal Circuit Short to Ground
DTC B3951 05: Right Rear Turn Signal Circuit Short to Battery or Open

Your best bet ,take it to a qualified repair shop.

Yes - the fast flashing is a warning that a bulb is burned out. Change the bulb (be careful to put it in the same as the old one as it probably is 2 bulbs in one , parking and turn/stop) and you should be fine.

Perhaps a dicky connection somewhere. Perhaps corrosion, even moisture in the connection plugs. Inspect all connections to your indicator lights. Also check for worn or damaged wires. Also Have a look inside the lenses of the lights to see if the the globes are corroded or have water ingress etc and causing shorts to other wiring within the lighting circuits.

You may also consider turn indicator lever to on to indicate truniong right, make sure the engine off. Have someone watch right indicator and literally grab the plugs/leads to the indicator globe and give them a shake to see if the fault goes away. If it doe stop intermitantly then it will help point you in the correct area.

make sure all the turn lights are working on your car. sometimes this is an indication of a burnt out bulb. you likely need to replace the flasher relay under the dash. if you have trouble locating it. turn on the turn signal that works and listen for it. once you know where the general location is put your finger on it and if it's clicking you have found the right relay.

start with the flasher that should solve your problem, if not then you will need the signal switch replaced, most of the time its just the flsher, good luck

one of the left turn signal bulbs is burned out. turn them on and look to see which one is out when you see one not on replace it and you are up and running again.

flasher relay is corect

Find the ground wire on one of the lights and add another ground wire to a good clean metal surface and see if that fixes the problem. It defently sounds like a ground problem at one of the lights.

put your right signal on walk round your car you may find that 1 of your bulbs is out

Obviously something got crossed up while it was apart! Either leave it alone and get used to it (I once had a 59Chevy impala that when left turn signal was on, entire dash flashed on and off with signal. I just laughed and left it alone) if it is still functioning properly. OR: take it apart again and look to see what got messed up!
Have fun (stop being such a neat freak!!!! a little dirt is good for the soul !!)