Old Horns Options

[zoomCat]

I've got some original Hella horns, original equipment on the car, but they've been silent for 30 odd years. Putting 12 volts across the lugs doesn't do anything.
Modern replacements look all shiny and new, even though it's something nobody else will likely ever see I thought I'd try to bring the originals back to life.



Opening them up they actually look pretty good.




I don't see any broken wires, and the corrosion is minimal. The sprung contact points on the right don't seem to be connected in a way that would allow the thing to move in response to the magnet.

Anybody know what I'm looking at here? Any particular diagnostics I can do?

[Superhawk996]

Note: I've never played with one of these - hopefully others with direct experience will chime in.

Operational principle is of a simple electromagnet. Contacts are a make/break affair in response to the diaphram moving.

Check coil continuity with DMM. I would suspect contacts should be starting from a closed condition.