Often during a divorce one or both parents will attempt to use the child against their ex-spouse. When this is the case legal counsel is necessary for the best outcome for the child. This next paragraph is an actual answer to a fathers inquiry of this type.
A 14 year old child has the right to testify in a custody hearing or trial, unless the judge makes a preliminary finding that it would not be in the best interests of the child. I doubt that finding would be made here based on what you’ve said. Given your income disparity and the apparent fact that your son lives with you, I would expect you to get some (not much) spousal and child support. However, your wife will try to force you to get better and full time employment. Try to find free legal help. Here in San Diego County we have a Family Law Facilitators Office which helps people in your situation fill out the forms. See if there is one in your county.
For additional information on this subject please visit this specific article on our web site: http://stanprowse.com/child-witnesses-in-divorce