Thanks,
I ordered a used k53k. It wasn't cheap so hopefully it will solve the problem when it arrives.
I haven't measured the resistance of the bad coil but I did swap the horn to confirm that the issue isn't with the wiring.
If the used coil doesn't work or of it does not match well then I will give Klipsch a call but I did read that the part was no longer available from Klipsch.