What are you using to measure temperature and humidity? I know you said something about buying a hygrometer. Get a thermometer instead. You just need 1 per enclosure.
Get this from Wal-Mart:
http://www.walmart.com/ip/Acu-Rite-I...mometer/896347
Measures 2 temperatures and humidity. It has a probe so the probe is placed on the hot side and the unit itself stays on the cool side.
Ball Pythons sometimes do go on hunger strikes. I'd pick up a digital scale while at Wal-Mart also. If he isn't losing any weight there's really nothing to be concerned about right now. Just keep trying every 5-7 days and eventually he will eat.
You also said something about his feeding area? Personally I'd just feed inside the enclosure if you are not already. A snake is way more comfortable where it spends 99% of his time. There's no need to move them to a separate enclosure to feed. After a snake eats the last thing it wants to happen is for you to pick him up and move him from one place to another. Stress.