[DHZIEMAN]

Voltage and current resistance can be a culprit! If the horn switch is not making good contact, if the wiring is sub par for the current, if the commutator is dirty, these kinds of electrical things just do not jump out! If your car has original wiring codes, the blue-yellow wire on the horn can be grounded to simulate the horn button. Make sure, regardless of my comment to know which wire on the horn connects to the battery!!!! If the horn does what it is supposed to do, then you have kind of isolated the problem. Next is the wiring to the horn button and then the actual horn button switch.