Legal Question in Family Law in California

Under California law, interest at 10% accumulates on any unpaid support. Your husband would be better served to get a loan to pay off this support arrearage assuming he could procure a better interest rate. If your husbands income has plummeted, this would be justification to downward modify any future child support. If he needs to modify the monthly payments on the amounts due for past support, the court may be willing to reduce the monthly payment. This monthly payment reduction will not cancel the support due or the interest that continues to accrue at 10%.

The answer to your question can be found in your question. "[E]very time he goes to court by himself," you say. The answer is to stop going by himself. I also have to wonder why you or he would expect the ex to give up the interest she is legally entitled to on money she was entitled to and he refused to pay. A guy who makes $22,000/month who runs up $45,000 in unpaid child support, and then refuses to just pay it, or take out a loan at a better rate than 10% to pay it, is going to have a hard time convincing a court to give him any relief even with a good lawyer. Now that his income has dropped, he's got a case, but with the history he has created in the court file, he better have a good attorney with him when he goes in and asks for relief.