I have noticed that at times my steering on my kia sedona lx 2004 gets stiff like the power steering is gone .. as well my coolant levels are fine but i have no heat nor is the a/c blowing cold air .. what could my problems be ?

This is a known problem and has been increasingly noted by sedona owners. Steering shaft becomes corroded making vehicle steer hard. They say due to salt but if you live anywhere it snows you cant avoid it.

Model/Build Years: KIA / SEDONA 2002-2005
Service Bulletin Number : TSB-019 NHTSA Item Number : 10027724 Summary Description : KIA: INCREASED STEERING EFFORT. IN AREAS WHERE HEAVY ROAD SALT USE OCCURS, INCREASED STEERING EFFORT AND NOISE (FROM STEERING INTERMEDIATE SHAFT) FOR SOME SEDONA. *PE

Some modern cars have an electrically driven pump to supply high pressure oil to operate the power steering. However, most cars have an oil pump for the steering which is turned by a belt from the crankshaft pulley. If the belt is loose or slipping, heavy steering will be the result, especially noticable at low speeds. Check belt for tightness, and check oil level is not low, possibly due to a leak?

Steve.