push button start and key out windows

How are your windows wired? 3 wire? 5 wire? Switching?

Most likely this is what you will need...... howevwer the Radio's accesory wire would not be for the radio...... It would go to the windows instead, the windows will have power available to them until the door is opened.

Wouldn't it be better if he used a relay in that push button scenario?  You would have to splice your starter wire (in the steering column harness) and connect as follows:

85: ground

86: +12 volts (fused)

87a: open

87: one end of the starter wire

30: other end of the starter wire

If you make a internet search for  Push button Starter you will find that there is already available several models and the instalation is very easy.

Isaac