Absentee fathers can disappear from your life for a number of reasons, ranging from a complicated home or employment situation to deliberate avoidance of support payments. It's usually possible to track down a "deadbeat dad" through a combination of online and offline resources, or the assistance of professionals. Whether you're attempting to re-establish financial support or just keep him "in the loop" about important family events, tracking him down yourself can be faster and more effective than waiting for the courts to do it.
Follow the Employment Trail
Researching the father's work history is often a good starting point. Most jobs require references before they hire a new employee, and previous employers are often contacted. Talk to his former employers and see if any references have been given and to what companies. Follow up on these leads, until you locate a current employer. Companies may be reluctant to give you this information, and you may have to involve the court.
Use Online Search Tools
If that doesn't pan out, try online search tools. The internet has become a huge resource for locating people. There are many search engines designed to search public records to find people. If the dad you're looking for is active on social media, look for him on mutual friends' pages under an assumed name. Another avenue is court files. If there's a possibility that the missing dad has run afoul of the law, search the court docket in surrounding counties to see if he's mentioned.
Turn To a Professional
If all else fails, hire a private investigator. They have many more resources than the average person does, but they come at a price. Private investigators usually charge a significant fee by the hour. It can be expensive but private investigators usually get the job done faster than you could do it alone, so it may be worthwhile if the matter is urgent or the sums involved are large. Check your yellow pages or speak to your local court about a private investigator in your area.