Horn doesn't work; How to not be an idiot in 10 easy steps

1. Horn does not work.
   • Clear visible mud dobber nests, no sound.
   • Meter test inconclusive; voltage changes on button press, but not to the expected 12v
2. Assume problem is combination of wiring and clogged horn
   • Clean horn more thoroughly and wire directly to battery for testing
3. Horn makes weak gurgling "poot" noise
4. Begin wire chase sequence
5. Remove headlight plate and headlight, disassemble headlight casing
   • Discover wire connections in headlight casing
   • Realize that I have no idea how a Rocket is wired
6. Discover aftermarket-looking mystery box inside of headlight casing
   • Disassemble, discover that it powers an out-of-date phone charger
7. Borrow stock Thunderbird horn from @UnicornRider and @Mad Dog to test wiring
   • No sound on button press; Feel onset of regret, activate brain
8. Check fuses
   • Horn fuse is burned through; replace fuse
9. Horn makes noise
10. Acquire new horns, wire into existing horn system; Reassembly pending

Son_Of_Dog said:

makes weak gurgling "poot" noise

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Mad Dog said:

You read voltage on a circuit with a blown fuse? I don’t think that is supposed to happen. Something else is shorting into that circuit or feedback from something going to ground when it shouldn’t?
Make sure you’ve got the meter set up right and check it again maybe.
The service manual I sent you is the same one in idk’s signature, in the back are wiring diagrams. Look and see where the horn circuit goes. If it goes through the ignition switch and still has voltage on it with the fuse out it would worry me.

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