Nissan Repair: 87 Sentra 4wd station wagon warning tone, nissan website, environment controls

Question
When I start the car it emits a warning tone that sounds like a seatbelt or 'door ajar' warning. The only way it stops is when the 4wd is engaged, as soon as you hit the button and before the servo reacts the tone stops. Disengage 4wd and it starts again right after the servo stops. It also lessens in intensity when the clutch is pushed, but only a little. It's connected to drivetrain somehow but I've torn the car apart with the original manual as a guide but there's no indication where the noisemaker is. It's up inside the dashboard somewhere very near to the firewall behind all the environment controls (yes, we took those all out too). My question is: what circuit is this warning tweeter on and how can I disable it? Thank you.

Answer
hello regarding your question on the warning alarm i have been trying to locate this type of car and then to locate a manual on it as i am located in the UK it is proving very hard to do so i am now logging on to the Nissan website in the us to try and locate the alarm module you speak of many thanks Michael