Light sensor problem on 2000 SSEi

I have a 2000 Pontiac Bonneville SSEi. Lately, when I start my car, the all lights are starts flashing. When I turn on the manual light switch, the blinking stops (resets). I can turn back to auto mode and after that; all system (twilight, etc) works properly. I’m suspecting the twilight sensor, but there must be another sensor too. Because my vehicle is in Europe now, it is hard to find a reliable service. I have to figure out what part need to repair my car. Anybody can help me here?

Thanks

Which lights are flashing? Are the DRL's functioning properly? The ambient light sensor is the (semi-translucent) dome in center of dash, this is for twilight sentinel operation.

Which lights are flashing? Are the DRL's functioning properly? The ambient light sensor is the (semi-translucent) dome in center of dash, this is for twilight sentinel operation.

All lights which are suppos to be on nightime. The dashboard light, low beam lights, tail lights. Thank for the help for the sensor, but I was able to lcate it, even I know how could I replace it. Pretty easy. But there is any other relay which could be bad and causing this blinking?

is there any aftermarket equipment like an alarm on the vehicle.and yes there is a number of components in that circuit like the body control module and it could be as simple as a loose ground wire?