If the multi-layered lights lit for LTA type, voltage DC. Wiring methods shown below:

For example:  

The following is a model:   LTA-205, Voltage: DC12V, layers; 3 layers, steady type.

There are four light lines. Red, yellow, green, black line

Description: The red line represents the red hood level, yellow line represents the yellow cover level, green line represents the level of green cover, the black line represents the negative supply.

For example: When the external power supply connected to the anode and the black line, the other three lines as the positive electrode, the cathode is connected to an external power supply. All the three lights are working, if the individual so red and external cathode connected to the red light, the other dictates. . . .

If equipped with a buzzer, the gray line represents the buzzer. The equivalent of a level. If you make it work, just the common line is connected to the external power supply positive.