It would have been covered by the 3 year, 36000 mile warranty.
It is absolutely covered. Unless you have cut some wires deliberately or paid someone to perform aftermarket work which damaged the vehicle the car horn is under warranty. You may want to claim the feature is a safety device and pressure the dealer from that perspective.
It is inside the under hood fuse box.
The 2011 Jeep Grand Cherokee includes a basic 3 year/36000 mi warranty, with a concurrent 5 year/100000 mi power-train and corrosion warranty. Emissions are covered for 2 years/24000mi, and roadside assistance is covered for 3 years/36000mi. Third parties often offer extended warrenties, each variable in the number of years, miles, and parts they cover.
The drivetrain warranty of the 2011 Jeep Wrangler is 5 yr./ 100000 mi.
The 2007 Jeep Wrangler has a 3 yr./ 36000 mi. basic warranty.
The 2011 Jeep Compass has a 3 yr./ 36000 mi. basic warranty.
The 2006 Jeep Wrangler has a 3 yr./ 36000 mi. basic warranty.
The 2010 Jeep Patriot has a 3 yr./ 36000 mi. basic warranty.
The 2011 Jeep Patriot has a 3 yr./ 36000 mi. basic warranty.
The drivetrain warranty of the 2004 Jeep Wrangler is 7 yr./ 70000 mi..
The 2001 Jeep Wrangler has a 3 yr./ 36000 mi. basic warranty.
The 2009 Jeep Compass has a 3 yr./ 36000 mi. basic warranty.