You can also rig a test harness by just unplugging the horns and run a set of wires to each horn from the battery, to see if they "Honk". That would eliminate the horns themselves (although I do not see how both would go bad at the same time). Removal of the front grill would help with easy access to the horns. Make sure you completely disconnect the horns fro the car wiring so as to not 'backfeed' any circuits!