A vehicle-mounted equipment carrier includes a base having a support member that is movable between an operative position and an inoperative position. An engagement member maintains the position of the support member, and is movable between an engaged position and a release position. The engagement member is movable between the engaged position and an intermediate position by a threaded connection with the base, is movable between the intermediate position and the release position by a sliding connection with the base. The shaft includes a threaded section that engages a threaded opening in the base, for providing movement of the engagement member between the engaged position and the intermediate position upon rotation of the engagement member, and an unthreaded section that moves the shaft axially within the opening for moving the engagement member between the intermediate position and the release position.