Watch this video. It's 6 minutes long, but at the end, the radio ends up working.
Consider antennas a disposable. Have extra. One time I week wacked the wire - tore it right in half. It's not like you can go down to the corner store and pick one up.
1) Take the head unit and hold tighly in one hand. With a leather punch or some similiar strong pointed object push outward softly on the copper outer contacts of the ANT connection. Basically just ever so slightly push the copper contacts outward slightly. This will allow them to make better contact with the base mount.
2) Take 2 strands of 18-22 gauge wire cut to 1/4" in length. Curve them both into a very slight "S" shape curve. Now take needle nose pliars and one at a time push the strands of wire into the hole in the head unit. What this will do is basically create a spring contact between the end of the ANT bore (hole in the head unit ) and the pin ANT contact of the base unit.
If you leave the unit installed this will last for several months. I have done it (2) times on my head unit and each time it has lasted about 6 months.
I am looking into replacing that small ANT connection if I can find the part but no success as of yet.