The JK heating complaint that wastes the most parts is a blend-door actuator. Hot heater hoses at the firewall and cold air at the vents, often with a clicking behind the dash, means the door that mixes hot and cold air is not moving. Mopar 68018109AA is the main blend actuator. Dorman 604-029 is the cross listed on the part page.
It is a small motor on the HVAC box, not a heater core and not the door itself. Owners replace cores and recharge the air conditioning when the actuator gear has stripped. If both hoses are hot, the heater core is getting coolant. The problem is downstream of that, in the box. If one hose is cold, look at coolant level, air in the system, or a stuck thermostat before you buy this motor.
This page lists that one actuator. Mode doors and the recirculation door are different motors. A click that continues after this actuator is replaced may be one of those. JL trucks are a different procedure. They often want an HVAC calibration before any parts get replaced, and this JK number is not the JL part.
What this category covers
- Main blend-door actuator 68018109AA for the JK
- The hot-hoses, cold-vents pattern that points here instead of the heater core
- Why an air-conditioning recharge does not move a door that has stopped
Parts in this category
Each row links to the child part page for that SKU: the current Mopar number, what it supersedes, aftermarket cross-references, failure symptoms, and whether to rebuild or replace. Every number on those pages cites a source.
| Part | Mopar # | Fits |
|---|---|---|
| Main Blend Door Actuator (HVAC) | 68018109AA | Parts catalogs list it as the main blend actuator for 2011–2018 JKs. Dorman says its actuators are... |
When to replace
Replace the actuator when both heater hoses are hot, the vents stay cold, and the click is at this motor. The factory procedure is a two-screw job, but the driver's lower dash and the floor duct come out first, so plan on an afternoon. If the door inside the box is broken, a new motor will click against the same broken door. That is a dash-out job, not another actuator. Do not replace the heater core because the vents are cold when both hoses are hot and full.
Safety
The actuator sits on the HVAC box under the steering column. Getting there means the lower dash comes off, which is the same area as the column. Anything with a yellow connector is an airbag circuit. Stop if the job reaches one, and leave column or airbag work to a dealer or a shop that does that work. Disconnect the battery before you unplug connectors near the column. A defroster that will not warm the glass is a visibility problem, not a comfort complaint, in freezing weather.
Related guides
Other systems
- JK Brakes & ABS
- JK Cooling
- JK Engine
- JK Steering & Suspension
- JK Electrical
- JK Body & Doors
- JK Fluids & Filters
- JL Brakes & ABS
- JL Cooling
- JL Engine
- JL Steering & Suspension
- JL Electrical
- JL Fluids & Filters
Part numbers change as Mopar supersedes them. Match the number on your old part, or run the VIN at a Mopar counter, before you order. Back to the parts lookup.