OEM Car alarm keeps going off

2001 Maxima with nearly 50k miles on it. Usually stays garaged. Ever since its been outside the past month the alarm goes off some nights and the nights it does this it does it repeatedly. Other nights it never goes off at all. Usually the nights it goes off are nights we've just come from using the car too. Tonight it was up to 90% humidity. Its now 84% humidity and it still did it. I'm guessing here about the humidity of course. Its 77 F outside too.

Has anyone else had problems with their OEM alarm going off when there is no sound or physical touching of the car from anyone or anything? Do you think the humidity could be a cause?

There are a few posibilities...

First, if you have a weak battery it can set off the system like your describing. Get the battery checked at any auto parts store.

Second, there are sensors everywhere on the car that may be going bad. Door sensors, hood, and trunk lid are the most common ones. Make sure they are all in tact, have all their rubber, and are functioning properly.

Thank you for the ideas. I think it was the passenger map light which was left on inadvertently. IE: draining the battery - Nice to see the car has a smart function like that... unless its a dumb function thats helpful. lol

... the humidity could be a cause?

Definitely yes.

Is it the cause? Needs careful inspection.

Remedy is new lacquer spray on the places where conductors are exposed to ambient air. As those conductors (not supply etc) which are connected to IC inputs, have a change in resistance (via shorting water droplets), it can lead into status changes - thus the circuitry will do the work it has been designed to = alarm by detecting this resistance change. (Of course this is a mfg quality problem, poor insulation)