Abstract: Aspects of this disclosure relate to flexible control of devices installed on a vehicle. A controller may be configured to control a plurality of devices (e.g., original equipment manufacturer (OEM) devices and/or aftermarket devices) based on input via one or more OEM-installed switches. The controller may be configured to receive input from the one or more switches and control, based on a currently activated functionality of the controller, either a first device (e.g., an OEM device associated with the one or more switches) or a second device (e.g., an after-market device). Activation and/or deactivation of a functionality of the controller to control a specific device (e.g., an OEM device or an after-market device) may be based on a predetermined sequence as input via the one or more switches.