Went out to start my 97 Toyota 4Runner and it wouldn't start. Security alarm going off, red blinking light, replaced battery, still won't start. tried locking doors, turning keys in ignition, etc. Everything google said to do we've done. Help!!!

Did you disconnect the battery?
Does it have an alarm and engine immobilizer?
Is the Security Light Flashing?
Did you reset it after you reconnected the battery?
Did you check for DTC codes?

https://www.google.com/search?q=1991+toyota+4runner+v6+reset+security+system

https://www.google.com/search?q=mobile+auto+electrician+near+me

..

Put it on a dealers computer and they can pull out any codes that auto zone can't. It could be a computer problem

sounds like you have a dead battery - does the starter solenoid click when you turn the ignition to the start position?

The alarm system somehow got activated , this is usually because the battery becomes discharged or disconnected try doing this:
Remove the key from the ignition
disconnect the negative battery terminal
put the key back in and turn to ON
exit the truck and leave door open
reconnect the battery terminal
get in and leave door open, if the alarm horn stays off it should start.

I would suspect ignition switch.All those things you mentioned , powerized by ignition switch.

lock your doors and close it wait till alarm resets and then unlock door with key and this should take care of you problem

If the vehicle has a 'Factory' alarm system, try cycling the jkey in the ignition ON-OFF (not to start), 5 times. This will defeat the factory alarm. This method is used in case the remote trasmitter battery goes dead, or the transmitter is lost.

This only works on Toyota Factory security systems, however.

after market alarms are a nightmare.

well first off when you change a battery you should use a memory saver so that things will not reset or clear themselves, BUT NOW ON TO THE GOOD NEWS, TO RESET THE ALARM, IF IT IS AN AFTER MARKET OR EVEN INSTALLED AT THE FACTORY ALARM, JUST LOOK UNDER THE DASH ON THE DRIVERSIDE, YOU SHOULD SEE A SMALL BUTTON PLACED IN AN OUT OF THE WAY SPOT, THAT IS THE VALET SWITCH, WITH THE ALARM GOING OFF, PRESS THE BUTTON AND HOLD IT IN, THEN TURN THE KEY, THAT SHOULD RESET THE ALARM BACK SO YOU CAN START IT BEING MOST ALARMS HAVE STARTER DISABLERS, AFTER YOU START IT UP SHUT IT OFF, IF YOU SEE THE LIGHT BLINKING FOR THE ALARM, YOU WILL NEED TO PRESS THE VALET SWITCH AGAIN IT SHOULD SHUT THE LIGHT OFF, IF IT STILL WILL NOT START, THEN YOUR ONLY OPTION IS TO TRACE THE STARTER LINES TILL YOU FIND WHERE THEY SPLICED INTO IT FOR THE ALARM AND DISCONECT IT THERE, THEN INSTALL A NEW STARTER, BUT THAT IS ALWAYS THE LAST RESORT. HOPE THIS HELPS....

I had a similar problem with my '94. Try disconnecting the battery, wait 30 seconds and reconnect the battery. This should reset the alarm.