Yes - you could be found in contempt and jailed for not paying the child support in full. However, it is up to your judge as to whether that would actually happen or not. Are you sure that your child support was calculated properly? There are several Alabama child support calculators on line. The is a link to one in our "Links" section of www.baileypoague.com. You can deduct the $360 payment for support of another child from your income. However, unless the lien for $400 is directly associated with child support (such as an arrearaqge) it is not likely to factor into your support calculation.
I practice in Virginia and will immediately suggest that you seek legal counsel in your home state. If an order is in place, you must make a good faith effort to honor the court order. If you cannot pay the full amount you must pay something each month until the issue is resolved through the court system. Typcially, to find contempt the court must conclude that you have intentionally failed to honor the order. If there is not enough money to go around, one could argue that you are not intentionally refusing pay. I would urge you to consider a support modification. Most statutes provide a credit for support payments made for other children or offer some basis for deviating from the guideline number. Speak with an Alabama family lawyer and see if you can petition the court for a support modification that limits your legal exposure.
This response is only intended for informational purposes and is not intended as legal advice or as a substitute for hiring legal counsel.