The Coleman Mach 8330A-763 is the go-to ceiling assembly for ducted RV air conditioning systems where 12V DC power is unavailable or a wall thermostat location simply isn't practical. This cool-only unit delivers reliable, even airflow through your rig's existing duct network -- no thermostat wiring required.
Many RV owners run into a familiar problem: the rooftop air conditioner works fine, but routing thermostat wiring or sourcing a stable 12V DC supply for the ceiling assembly isn't feasible -- especially in older coaches, slide-in campers, or custom builds. The Coleman Mach 8330A-763 solves that directly. Its manual control design eliminates the dependency on 12V DC logic boards and wall-mounted thermostats while still distributing conditioned air efficiently through a lateral ducted system.
The ADB (Air Distribution Box) ceiling assembly mounts at the interior ceiling and connects to the rooftop Coleman Mach air conditioning unit above. Cooled air is directed laterally into the coach's duct run for even distribution from front to back. This is a cool-only assembly -- it does not support heat pump operation.
No 12V DC or wall thermostat required. Operates independently for simplified installations and retrofits.
Directs airflow into the coach duct system laterally for balanced, whole-coach cooling coverage.
Integrated air distribution box channels conditioned air from the rooftop unit into the ducted run efficiently.
Dedicated cooling-mode assembly -- ideal for coaches without heat pump rooftop units or supplemental heat systems.
The ceiling assembly is the interior half of your Coleman Mach rooftop air conditioning system. It houses the evaporator blower, air distribution plenum, and (depending on model) the control interface. The rooftop unit handles refrigerant and the condenser; the ceiling assembly handles interior air movement and control.
The 8330A-763 is specifically for lateral ducted installations. "Lateral ducted" means the ceiling assembly discharges conditioned air into a horizontal duct run that spans the length or width of the coach -- versus a non-ducted unit that simply blows air straight down into one zone. If your RV has ceiling duct registers spread across multiple rooms or zones, this is the correct assembly type.
The manual control designation means fan speed and cooling are operated via controls on the ceiling assembly itself, not by a remotely mounted wall thermostat or a 12V DC-powered digital control board. This makes it well suited for:
This ceiling assembly is designed as a direct replacement or upgrade component within the Coleman Mach ducted AC ecosystem. Confirm your rooftop unit is a compatible Coleman Mach model (typically Mach 8, Mach 8 Plus, or 8330-series rooftop units) before ordering. The ceiling assembly and rooftop unit must be matched for proper refrigerant line and electrical connections.
The ADB (Air Distribution Box) is the plenum section integrated into the ceiling assembly that routes cooled air from the evaporator into the duct work. In lateral ducted configurations, the ADB is oriented to push air horizontally into the duct run rather than straight down. This design supports longer duct runs and multi-zone distribution common in Class A and Class C motorhomes, as well as larger fifth wheels.
The 8330A-763 ceiling assembly is rated for cooling operation only. It is not compatible with heat pump rooftop units in heat mode, and it does not support electric heat strip accessories. If your rooftop unit has heat pump capability and you want to use it for heating, you will need a heat pump-compatible ceiling assembly instead.