i have a 1988 nissan 300zx non-turbo. i have a factory security system and i have been recently messing with the battery due to me fixing the car. when i turn the key in the ignition the car will not turn over. the security light blinks on the dash and i have tried locking and unlocking the doors with my key. NOTHING HAS WORKED. is there any way to just take it all out or trick the security system into thinking it is able to give a spark? i need all possible answers

 

yes, remove the passenger seat and locate the box that says "theft warning" and just unplug it.

Easy peasy. The starter kill relay kills the starter when powered so unplugging the alarm unit will disable this.

Before you do this though, have you tried unlocking the rear hatch with your key? pull off the plastic cover behind the tail lights and see if there is a wire lose near the trunk latch.

 

what i do to start it is to press in the brake and move the automatic gearshift then i put it back into park and then it starts fine but i have to do that everytime. i will definetly try what you have said to do.