Electronic Siren (490-0488F) Installation Faxback Doc. # 6594 Because the Siren is weatherproof, you can install it outdoors. However, do not position the siren with its horn pointed upward so that it collects and retains moisture. In a mobile installation, be sure the siren is not mounted so that rain is forced into the horn when the vehicle is moving. Also, do not mount the siren directly above heating vents. The adjustable mounting bracket lets you position the siren as necessary. (LB/all-07/11/94)