ttina -

It is clear as day to me what your ex is doing. He has a trade/skill that he is indeed using to make money. He just has his customers pay him cash, so that there is no paper trail (w-2's or 1099's or even bank records). He is even trying to use his lack of income (haha) to try to defraud the gov't into giving him disability benefits. Dirtbag all around!

You've got a couple of options here, if you want to pursue them:
Do a brainstorm about all the things he spends money on - eg the trip with your son. Then, document the things he does (ie keep a journal) that would seem to contradict a back injury. When you go to his house to pick up/ drop off your son, be observant - do you notice cars there that are not his that he may be "working" on? Take notes. Present all of this to the judge - and he will surely side with you.

That said, how are you going to ACTUALLY get blood from this stone? As you say, no wages to garnish etc... In a way, you almost don't need the judge. Once youhave a nice little stack of documented "notes," I would send them to your ex with a note that says your next step is to share the notes with the IRS and Social Security Office and police (re fraudulent disability claims), unless he starts sending cash your way so that your son doesn't have to lead a bare bones existence.

Sometimes you gotta stoop to their level. Just be careful not to involve your son in this - even to the extent of picking his brain for "evidence" - that's just not a healthy road to go down for either of you.

In the interim, have you tried the following tact? "When jr. is with you this weekend, can you take him to the mall and get him some new tennis shoes? He desperately needs them and we just can't afford it right now...." OR: "The fee for junior's summer camp is $X - here is the form to send in with the money. He really enjoys this every year..."

Another option is this: Make yourself forget about the money. This sounds hard, but actually might be the easiest and healthiest route for you, becuase it doesn't sound like the "system" has a way of making him pay up. Just because you choose to forget about it, does not make what he is doing "right" or absolve him of any guilt - but will take a load off your psyche. I'm sure you know a family or a single mom who gets by on less than what you do. Make them/ her your role model. Also, don't be too proud to accept or ask for help from your family. My sister in law had a child, and the father was an under-employed abusive alcoholic who already had 4 kids with 2 other women. She knew she didn't want this man in her kid's life (he beat her while she was pregnant!) so she has foregone any child support. It's tough for her, but she words really hard, and has her parents financial and logistical support (free daycare, transport, etc....) We set up a college fund for my neice; the other uncles make sure the little girl gets extra presents from them at X-mas and b-days....It's what family is about.

Good Luck to you.