I installed a new dash wire harness and new engine wire harness but my horn isn't working. The horn and relay are original. The car is a 70 Roadrunner. The horn worked when tested when I first got the car running a few months ago. The horn does nothing now. The horn relay clicks when the horn button is pushed but still nothing from the horn. I ran a wire from the battery directly to horn and still nothing. Is the horn no good, the relay no good or both?