Installation needs to be done according to the instructions provided in the installation manual. There are two options for connecting the blocking relay:
Normally closed (NC) contact: the relay needs to be continuously powered on in order to prevent the vehicle start. If tampering or a malfunction occurs, the relay will enter its unblocked state. If the vehicle needs to remain in a blocked state when inactive for a prolonged period of time, the relay’s current draw will increase the vehicle’s battery discharge rate.
Normally open (NO) contact: the relay needs to be powered on in order to start the vehicle. If tampering or a malfunction occurs, the relay will enter its blocked state. In its blocked state, the relay does not consume power, thus when this installation option is used for vehicles that remain inactive for a prolonged period of time blocking is recommended when locking the vehicle.
Separate installation manuals are provided based on the connection method and the devices' configuration needs to be done accordingly. Installation manuals containing the instructions to make the connection to the normally open contact will have the “ATH-INV” tag in the title. Full list of how the vehicles should be connected and what configurations should be used can be seen following This link.