In the 2008 dodge avenger, you'll find the fuse box that controls most interior components underneath your hood. it's to the far right side of the engine compartment, near your air filter assembly. if you're curious as to which fuse controls which component, you ought to be able to find a legend on the underside of the cover. some components controlled by fuses in this box include the brake vacuum pump, ignition switch, power mirror switch, battery feed, instrument panel, cigarette lighter, radiator fan relay, sunroof (if equipped), radio, horn, heated mirrors (if equipped), antilock brakes, and passenger door module. essentially everything you're looking for should be located here, so as long as you've narrowed down the faulty component, you should be all set.
There are two fuse boxes on the 2008 dodge avenger. the first is located under the hood, while the second is located under the dashboard below the steering wheel.