Coleman-Mach 8430-3861 Air Conditioner Control Box (Cool-Only) – For 8330/8430/7330 Ceiling Assemblies

The Coleman-Mach 8430-3861 is the OEM cool-only control box used with 8330 / 8430 / 7330 ceiling assemblies. It replaces the earlier 8330-3851 module and provides the correct relay/control logic for rooftop AC units controlled by a wall thermostat (cool-only). If your plenum came as part of a kit like 8430-6334, this is the control module it pairs with.

• OEM direct replacement for aging or failed control modules in 8330/8430/7330 ceiling assemblies.
• Cool-only configuration for systems without a heat strip or heat pump.
• Wall-thermostat compatible (Coleman-Mach standard 12V control circuits).
• Supersession: replaces older PN 8330-3851.

What’s Included

• (1) 8430-3861 control box (cool-only)
• Factory harness/connectors attached (as supplied by Coleman-Mach)
• Basic install instructions (in kit or downloadable)

Specs

Manufacturer	Coleman-Mach (Airxcel)
Part Number	8430-3861 (replaces 8330-3851)
Function	Cool-only control module for wall-thermostat systems
Voltage / Control	12V DC control circuits; line-voltage switching via internal relays
Compatible Ceiling Assemblies	8330 / 8430 / 7330 series (non-ducted & ducted variants as specified)
Thermostat Type	Wall mounted, cool-only (fan speeds & compressor)
Heat Capability	No—use (9330C755) for heat-ready applications

Compatibility

• Designed for 8330 / 8430 / 7330 Coleman-Mach ceiling assemblies.
• Supersedes: 8330-3851.
• Works with: Coleman-Mach wall thermostats for cool-only systems.
• Does not replace: ceiling assemblies (e.g., 8430-6334) or heat-ready control kits (9330C755).

Installation Notes

1. Disconnect 120V AC and 12V DC power to the system.
2. Drop the ceiling assembly shroud and locate the existing control box.
3. Label thermostat, sensor, and rooftop harness connections (photos help).
4. Swap in the 8430-3861, moving each connector one-for-one.
5. Restore power and test: fan speeds, compressor engage, and thermostat operation.

If adding a heat strip or converting to heat-ready later, use the correct heat-ready kit (e.g., 9330C755) and compatible thermostat.

Frequently Asked Questions

Is 8430-3861 the same as 8330-3851?
8430-3861 is the current/replacement part number for the earlier 8330-3851 cool-only control box.

Will this work if I have a heat strip?
No. For heat-ready (electric heat strip) systems, use a heat-ready control kit like 9330C755 with the proper thermostat.

Does this include the ceiling assembly?
No—this is just the control box used inside 8330/8430/7330 ceiling assemblies.

RVupgrades Support

Unsure whether your system is cool-only or heat-ready? Call, chat, email, or text RVupgrades and we’ll confirm the right module based on your rooftop model and thermostat.

OEM Coleman-Mach 8430-3861 cool-only control box for 8330/8430/7330 ceiling assemblies. Replaces 8330-3851. For wall-thermostat systems without heat strip.

Related: 8330/8430/7330 ceiling assemblies · Coleman-Mach wall thermostats · Heat-ready control kits