Roof air parts?

[Scott Forman]

My coach has all three original roof airs. When the plastic cowl is
removed on the roof, there is a small electric motor that is connected
to a shaft that turns the fan that blows air over the coils. On one of
my units, that shaft corroded to the point that it finally broke off
right at the fan hub. As a result, the A/C will no longer cool. One
of my other units has the same problem developing, as it appears that
its shaft may break off soon (getting thin).

My question is...is there a part I can replace? The motor spins fine,
can the shaft be removed from the motor and replaced? Or, if not, can
the motor/shaft assembly be replaced? Or am I looking at replacing 2
A/C's?

Scott Forman
86 PT38
Memphis