California. I have shared custody of my 5 year old son. His mother has not made any contact with me or my son for 4 months. Our prior arrangement was that I would drop my son to my ex-wife's house on the alternating days that we had arranged and pick him up in the morning and take him to school. her work schedule started getting erratic so she started calling me and telling me what nites she was home, eventually the phone calls no longer came. I have made numerous attempts to contact her. So now four months later what can I do to get full custody? of my son. My finances are tight right now what is the simplest and cheapest way to go about this.