1995 Nissan Altima Factory ALarm

HEllo, I was installing car stereo on my friend's 95 Nissan Altima. WHen I removed the battery negative, the alarm went off for a few secs. I started working on the stereo and after sometime since we had to go and close the window, I reconnected the battery terminal and the alarm went off again! Now every time I open the door the alarm goes off. The owners manual says to deactivate alarm I shd open the door or the trunk with the Key. But that is not helping.I tried it several times. Can some one help me!! Is there a way to completely deactivate the alarm system?? or is there any other solution? Thanks Alpesh

There is a GREEN/ YELLOW wire in the driver's side kick panel that if pulsed to ground will disarm the alarm. it should be connected to the key cylinder on the outside of the driver's door. It switches to ground when you turn the key to unlock the door. The switch may be broken inside the door. The factory keyless entry remote should also disarm the alarm.sparky

THanks Sparkie, I ll try this tomorrow during the day...My friend just bought this car and he did not get any remote with it. Did this car have keyless entry? Or was it an option. Is there a way to check and if we find it has is there a way to get a factory remote (apart from dealer)?