Ted,
If you want to try wiring in a different mic (and flipping
a switch under the cover of the radio to change to
the other mic style setting), the wiring diagram is
available at:

http://www.wingsandwheels.com/AR4201%20Manual.pdf

Assuming here that it is a 4201 you have. Otherwise,
Rex's comments are good. Try installing an identical
radio and see if you have the same problem. I suspect
you will. I bet Rex or Tim or one of the guys could
get a replacement mic on its way to you tomorrow.,
as I suspect that is where your problem really is.

V2C coming soon, huh? Nice! I suspect you will like
it a LOT!

Steve