Resetting security system

My 1986 300ZX has a continuous flashing security light that is killing my battery in less than a 24 hr period. What can I do to make it stop.

Your battery may not be holding its charge. Charge the battery and take a voltage reading. Then after a few hours take another reading andsee if the voltage has dropped. If that is alright, refit the battery to the car. turn off all the electrics anddo a voltage test. If the battery is discharging then ou will have to find what componant is drawing the voltage. I normally check the boot through the rear seats first.

1999 chevy tahoe security light goes on while im driving does
not seem to cause any problem

mine was doing that and it was cause of a relay in the fuse box under the hood got moisture in it and was shorting out i caught it flashing the lights once and sounding the horn like it was hoarse replaced the relay like 4.95 at autozone and it fixed the problem

Check door and hood latches to make sure they are actually closing properly. It could be a faulty security module, but more likely it is a broken plastic piece that clips onto the back of a door lock.

Also, if you want to test each security sensor before ripping everything apart, you can put the key in each lock and turn it to about 2:00. The light should go out completely but then begin flashing again when you remove the key. If you can get the light to go out while doing this on each door and hatch lock, then you probably have a bad hood sensor.
Otherwise, the lock that does not turn the light off is the one with the bad sensor. Also found that the alarm will not work if the security light is flashing.

there is a red blinking light it is a reset button just push it and it should cut off. if not the button is bad and you have to go to a junk yard to get it because mitisubishi doesnt stock this part anymore!!!

I just had this to happen to me - here's what you do - when it will not crank - turn your key over to ACC and let it stay on here for 15 minutes, the THEFT SYSTEM light will stop flashing. Turn your key back to OFF then turn it over as normal when starting and it will start right back up! Found it out from an auto store! One lady paid over $700 and then found this out!!!