[jfcrash]

In the last several weeks I experienced the same issue when installing my two horns in the '35....very loud on the work bench powered by a battery charger, but only made a clicking sound when on the car....grounding the bl/yellow also made them sound.

I was advised to disconnect one horn, remove the cover on the other and slowly adjust the points (and clean the points)...in my case in worked and did the same on the other horn...problem solved. This is a simple test and a bit easier than running wires to a auxilliary horn button or relay.

Hope this helps, Jim