34 car horn construction

[Bruce in southern OH]

Should have asked first, here is what I have found after several days of on and off work. I placed my restored horns on car, (Don and I placed new chrome horns, horn caps and fixed diaphragms) looked great. We had bench tested them and they sound good, now I installed the new wire from horns into engine compartment and plugged into the wiring harness. Next I connected the yellow wire to hot terminal and the horns BLOW, without pushing the button. Removed the horn caps and looked at everything, tested and found that everything in horn reads to ground. Removed horns today and traveled to Don P.'s garage and we tested, took things apart, replaced parts several times and then decided that I would have to use a starter solenoid that has the battery terminals and uses ground to make and break(like a 41). THEN I looked in Macs and found a note that if you purchase new horns from them to USE A HORN RELAY. Now I know my horns must have been replaced years and years ago. How were the original horns constructed? Were they insulated from chassis ground with bushings or what, learning everyday, thanks for your time, Bruce