OK pulled the horns this morning. Tried to bench test applying direct current to one of the pins on the horn and ground to the other pin to see if either horn would operate. Neither one did so I am assuming that both the high and low pitch horns are toast at this point.

Also attempted to check the voltage at the fuses with the horns removed. I got a full 12 volts at the 15 amp fuse in the passenger floorboard when the horn switch at the steering wheel was activated with the ignition on. No voltage otherwise.

With these tests would it be safe to say at this point that I need to replace both horns and monitor the steering wheel horn switch to ensure that it continues to work properly?