Not A Honker

Can ’70 ’Cuda horns be rebuilt? I tested
mine by applying 12V to them
(individually). One worked and
one didn’t. Is this the correct
way to test them? If they cannot
be rebuilt, who sells them? I
have checked numerous companies
and haven’t found anything
but Road Runner horns.

You are testing them correctly.
While I’d never say that
a component cannot be rebuilt,
I will say, in this case, that it
clearly is not time/cost effective.
All 1966 through at least
1974 Mopars, except the obvious
Road Runner, used the
same horn pairs: P/N 2808869
was the high note, 2808868 was
low. (Some base models had
just the single low note horn.)
Good used ones are easy to
find. One source that comes to
mind is tonysparts.com