Replacing power antenna mast—only goes up halfway and stops; how to fix?

What is your question?

The electric motor for the power antenna works; but, the mast only goes up half way. If necessary, I can convert to a fixed (manual) chrome fm/am antenna if necessary. The antenna's mount is in the right passenger fender; you an get at it under the hood of the van. The radio was working fine, but, since the mast only goes half way up I only get static right now.

What makes this problem better or worse?

Antenna “sticks stops half way up, but will retract all the way back down.

How long has your 1995 GMC G2500 had this problem?

A couple weeks