Hi mills1488,
Welcome to the Heartland Owners Forum.
Heat registers are typically on the floor. Air conditioning ducts are typically on the ceiling.
On toy haulers, it's quite common for the heat registers to put out lukewarm air due to the distance from the furnace. Many people supplement with ceramic disc or other types of heaters.
If you're not getting any air out of the floor registers, you may have something blocking airflow - perhaps a kink in the duct work.