Did the 1975 come with two, or just the one horn?

2

Not sure. Base model may not had two. You have to have a crossover harness to plug in for the second horn.

I thought dual horns were part of the appearance group. My 73 only had one but the body harness had terminals for the second one but they were fold back and taped off just like the wire for the intermittent wiper feature. I have no idea if that applies to 75 though.