Usually when I press my key fob the horn would give one good blast. The other day I pressed it and it was a very sick sounding high pitched noise that sounded nothing like it should. I checked all my hoses and everything looks good.
Took a quick video while pressing the key fob.
It just dont have the deep sound it did before, now instead of making someone jump, it would hurt their ears. BUT on long blasts, I can pick up a faint high pitched noise along with the blast.
Are you keeping your finger on the remote button or can you keep your finger on the button?
It could be like O6Z said solenoid or Horns.
It could also be the remote fob battery needs changing? It has not got enough power to transmit a strong signal to the receiver? And therefore is only operating for a fraction on the time?
(however, this theory is only proven if your able to keep your finger on the button normally to honk long honks!)