Security light

[Malachias]

Bonny SSEi 1992 (Supercharger)

The security light (yellow light) in my dashboard have been working fine since
I bought (brand new) this car and still working whem you open the door (blinks) and when your lock the doors by remote it still on for 30 seconds and go out as should to be.
Today I crank the engine , it start to running and the security light stay on
all the times. I turn the ignition off and the light go out . it´s ok.
I crank again, the engine start to run flawless but the light still steadily on all
the time.
Any suggestion ?
My thanks a lot in advance.
Malachias (Brazil)