Radio Harness Testing

My car came with a PTT and a harness, I bought radios, an adapter, and a helmet kit.

The radios work fine. I plugged the PTT into the harness and the radio adapter into the harness and radio..

Press the PTT and nothing.

The radio knows it's externally wired - no sound out of the speaker when plugged into the harness.

So now its trying to determine if its the PTT or the harness itself.

Anyone have Pin out info? The PTT is a standard 3 pin.

Does the PTT work if the headset isn't plugged in? or do I need to install everything.

Suggestions welcome ;)