Ram A/C Temperature Probe (2007-2021) 3rd & 4th Gen – 68004239AA

Your A/C is cycling erratically — blowing cold then warm, or the system cutting out before the cab is fully cooled. On 3rd and 4th Gen Ram trucks, the A/C temperature probe (also called the evaporator temperature sensor) monitors refrigerant temperature inside the evaporator core. When it fails, the A/C control module loses accurate data and can’t regulate the system properly. This is the OEM Mopar replacement, direct factory spec.

Part Number: 68004239AA

Fits:

• 2007–2009 Dodge Ram 1500, 2500, 3500 (3rd Gen)
• 2009–2018 Ram 1500, 2500, 3500 (4th Gen)
• 2019–2021 Ram 1500 Classic

Why replace it?

• A/C cycling on and off erratically
• A/C blowing cold then warm without input changes
• System cutting out before the cab reaches set temperature
• A/C-related fault codes stored in the HVAC module
• Evaporator freezing up (sensor not signaling the system to cycle off)

What this part does:
The temperature probe sits inside the evaporator housing and sends real-time temperature data to the HVAC control module. The module uses this signal to cycle the compressor on and off — keeping the evaporator from freezing and maintaining consistent cabin temperature. A failed probe disrupts this feedback loop.

OEM Mopar quality. Direct plug-and-play fit. No programming required. Fast shipping from Ram Parts USA.