Why does the security light flash all the time causing the battery to drain on 86 Nissan 300zx?

Answer 1

I would check your door jam switches starting with the drivers door. If the switch is bad the vehicle thinks the door is never shut. Remove the switch and put a temporary jumper wire across the two terminals, if the light goes off that is your problem. Is the problem intermittent? Do you also have the problem where the door ajar warning light flashes, causing the interior lights to go on and off? I had this problem, which was very noticeable while driving over bumpy ground. The warning light and interior lights would flash with each bump in the road. The flashing was accompanied by the sound of a relay switch clicking open and closed. This problem was caused by a rusty bolt that holds the switch that senses when the door is open. The switch in question is the one you can push with your finger while the door is open. Believe it or not, the switch's fastener bolt needs to complete a circuit with the car chassis, otherwise the switch won't work properly. If the bolt develops even a thin layer of oxidation, small vibrations can break the circuit between the bolt and the switch, causing the security sensor to trip. SOLUTION: Unscrew the fastener bolt of the door ajar switch and spray the bolt and hole threads with electrical part cleaner, then screw down the bolt tightly, but without stripping the threads. I tried this with my car running, and could hear the interior lights relay switch clicking every time I touched the bolt with my screwdriver. Non-corroding bolts would have been nice. I removed half my Z's interior paneling looking for the problem.