'98 Altima, no remote. Alarm enabled itself. How do I disable it? Possibly permanently?

Answer 1

Aftermarket alarm? You need to find out what kind of alarm it is (brand name). If you don't know or can't find out, you can always try to find the fuses, usually under the dash, and pull them. They won't be in the factory fuse panel, but in-line on aftermarket wires. If you don't feel comfortable doing that, get it towed to a car audio/security shop.

Answer 2

all aftermarket car alarms have a valet mode switch on the bottom of the dash.
most likely its going to be under the left hand side of the steering wheel under the dash.
its kinda hard to reach so that car jackers cant find it easily but if you get under the steering wheel with a flash light it should be easier to spot.
the point of the switch is for when you need to deactivate the alarm.
like when your alarm remote brakes and you have to use your key and the alarm goes off, you flip the switch and it deactivates.
or when you send the car to the mechanics you deactivate it so the mechanic doesnt get the alarm goin off.
just open you car with the key and the alarm will go crazy then get under the steering wheel find the switch and switch it once or twice depending what brand you got.
and there you go its deactivated.

Answer 3

Factory Alarm Disarm green/yellow - smart entrance control

The smart entrance control unit is located to the right of the steering column. It is black or blue in color.

To permanently disable the unit you need to ground this wire.
(Only for factory alarm system)