The OEM-spec ceiling assembly that connects your Coleman Mach rooftop AC unit to your rig's duct system. Built for cool-only operation and wired for standard 24 VAC wall thermostats, this is the right replacement when your original ceiling box cracks, warps, or the damper mechanism fails.
Coleman Mach's ADB (Air Distribution Box) ceiling assemblies are the interior half of their rooftop air conditioning system. The rooftop unit pulls heat out; the ceiling assembly distributes conditioned air through your rig's lateral duct network and returns warm cabin air back up through the return plenum. When the ceiling unit is damaged or the damper linkage breaks, cool air delivery suffers even if the rooftop compressor is running perfectly.
Part number 8330A743 is a lateral ducted configuration, meaning conditioned air exits through side ports that connect to the horizontal duct runs in the ceiling -- the standard layout for slideout-equipped coaches and longer floorplans where a single central register isn't enough coverage. This unit is cool-only; it does not support heat pump or electric heat strip operation at the ceiling assembly level.
Side discharge ports tie directly into existing horizontal duct runs for even airflow distribution across multiple registers.
Compatible with standard 24 VAC RV wall thermostats. Works with Coleman Mach analog and digital 24 V thermostat families.
Air Distribution Box design integrates the damper, blower housing, and return air plenum in a single ceiling-mount unit.
Engineered to mount to the same roof opening and wiring harness as original Coleman Mach rooftop units -- no adapter kits required.
This ceiling assembly is rated for cooling operation only. It does not include a heat pump reversing valve control board or electric heat strip. If your system currently provides heat via a heat pump or electric strip through the ceiling unit, this replacement is not a match -- you will need the heat-cool version of the ceiling assembly for your model. For supplemental heat in a cool-only system, a separate furnace or heat strip in a different zone handles that duty.
This assembly is designed for 24 VAC wall thermostats -- the standard low-voltage control signal used on most Coleman Mach systems from the early 2000s through current production. It is NOT compatible with 12 VDC digital control systems or proprietary one-wire thermostat protocols used on some newer coach integrations. Verify your existing thermostat outputs 24 VAC before ordering.