The low battery light appears frequently. Some

All the functions that you are talking about are controlled by the BCM. This is an expensive auxiliary computer in the cabin.

Turn signal flasher isn't working

Those lights are on different circuits. The high and low beam lights are powered thru the headlight switch, the turn signals, brake, and hazards go thru the turn signal switch.
I would want to know if each circuit has power at the switch that controls it.

one the your light bulbs have a broken contact or the ground shorted out

have your charging system checked. your alternator may be an issue.

I suspect there is a problem with the turn signal/ hazard switch. turn the turn signal on left or right, if it doesn't flash, grip the hazard button and gently wiggle it around, if the signals start flashing, replace the turn signal switch. The Brake lights are wired through the turn signal switch, if the 3rd brake light works, the brake switch is OK. I don't think it has anything to do with the anti theft system (at this time)

YOU HAVE FAULTY COMBINATION SWITCH WHICH IS TURN SIGNAL SWITCH AND DIMMER SWITCH.YOU NEED TO DISABLE AIRBAG IN THE STEERING WHEEL.JUST TURN OFF RADIO REMOVE NEGATIVE BATTERY CABLE LET AIRBAG DISCHARGE AND THEN REMOVE COMBINATION SWITCH FROM THE STEERING COLUMN.

You could have a bulb blown or a fuse blown or a turn signal switch that has went out.

replace the positive battery cable, trust me on this one have done dozens of 91 and 92's.

This may due to the battery get the battery checked , if you face the same problem again then the on board computer may be faulty ..........................................