The ART-2000/2100 has a dipswitch with eight settings used for installation functions. The dipswitch must have the correct configuration for the radar to perform properly. Please see the images below to locate the dipswitch on your unit.

Depending on the position of Switch #2, the scanning function may be disabled. You must verify that Switch #2 is in the "ON" position. The setting is on when the switch is positioned towards the center of the unit.