Yes, it is possible to retrofit a 2004 Harley-Davidson Fat Boy with cruise control. However, it should be noted that Harley-Davidson did not offer factory-installed cruise control on the 2004 Fat Boy model. Adding cruise control to a motorcycle that does not have it as a factory option generally requires aftermarket components and modifications.
There are several aftermarket companies that offer cruise control kits specifically designed for Harley-Davidson motorcycles. These kits typically include a control module, throttle-by-wire interface, handlebar-mounted switches, wiring harness, and installation instructions.
To retrofit cruise control on your 2004 Fat Boy, you would need to acquire a compatible aftermarket kit and follow the installation instructions provided. It's important to ensure that the kit you choose is designed to work with your specific motorcycle model and year.
Since the availability and compatibility of aftermarket kits can vary, I recommend reaching out to reputable motorcycle accessory retailers or contacting authorized Harley-Davidson dealerships to inquire about suitable cruise control options for your 2004 Fat Boy model. They should be able to provide you with more specific information and recommendations based on your motorcycle's configuration.