I have a 75 1.8t connie 2003, the only thing I don't like about the car is the single horn.What do I have to do to change it to twin horns? tia. Mel.
Two or more options. Both require removal of front bumper assembly.
1. Install high note horn to compliment the currently installed low note horn. I believe these are still available. This requires splicing into the existing wiring on the low note horn and running it across the front of the car to where the high note horn is to be installed. Part number YEB 101130
2. Install something like the Stebel Nautilus Air Horn which I have, again the wiring is spliced into the wiring for the existing low note horn and mounted on the nearside in a convenient position, you may have to make up your own bracket for this. The low note horn should be left in place as there is a momentary delay for the air horn to work, also tapping gently on the horn button will operate the low note horn if you want to be polite, whereas holding the button down engages both horns which can be a bit rude.
You'll find this document useful. triple-horn-conversion.html