1983 Toyota Tercel horn

My horn was always intermttent. I replaced it. Same thing. At the moment it is not working at all. There is battery voltage to one lead disconnected from horn. The other lead is 0. When connected to battery both sides have voltage. Question1 Why are the posts of the horn shorted when tested with an ohmmeter? Pressing the horn button does not change the voltage on either side. I had the horn tested at an auto place. It's fine. Should I attempt to ground the lead inthe horn button compartment. How do I do it? I connected new wires from the female part of the connector to the horn. Help. Thank you, George