today at lunch, i was trying to start the car to run an errand and got no turning of the engine, but the door ajar light started to blink rapidly, and i was getting a noise that sounded like the blinker from the driver side headlight area. when i checked up front under the hood, i also noticed the turn light was actually flashing rapidly. i thought it was a short in the light so i tried to disconnect it. then the alarm started to go off randomly. i tried to turn off the alarm with the remote (factory) and it just kept going off. i ended up disconnecting the battery until i had time to look at it.
my buddy gave me a jump and my fiance went to pick up our kid but i told her to keep it running. she came back and cut the engine and the same issue started. random dash lights blink, no turning of the engine, and what sounds like the turn signal clicker from behind the headlight.
coworker thought my remote battery might be going south so i switched it to no avail. seems to run fine when jumped although it died while parked when we got home. then the blinking and noise started again.
i have an older Tacoma and have had, and fixed, the starter solenoid contacts issue but this is not the same. the fact that the lights blink like crazy and the alarm goes off randomly makes me think there's an issue with the alarm. the dealership said the battery might be dying and causing weird electrical issues. maybe the alternator?
any suggestions? we have an appointment for a 90k service at the dealership tomorrow, but i don't want them to try and fix this if it's simple (and cheaper for me to fix

). thanks!