The 2012 dodge avenger horn relay can be found in the fuse panel that is located under the hood. the relay will be able to be spotted using the guide that is on the cover of the fuse panel. if your horn is not working then the first thing to check is this relay. the next thing you should check is the wiring to the horn. if it is frayed or loose then you will need to repair or connect it to the actual horn assembly. the last thing to check is the actual horn unit itself to see if it makes any noise when it is connected directly to 12 volt power. if it does not then it is likely that the horn has burnt out and will need to be replaced.
The 2012 dodge avenger horn relay is located in the totally integrated power module located under your hood.