Four Seasons 74933 HVAC Heater Control Valve

Four Seasons 74933 Heater Valve Overview

The Four Seasons 74933 heater valve is a rotary electronic heater valve built for precise coolant flow control in the HVAC system. It uses an electric bypass design with a plastic housing and 3 connectors, making it a direct-fit service part for select Cadillac and Chevrolet applications.

Four Seasons Heater Valve products are part of a focused line of HVAC temperature control components. This line is backed by more than 50 years of mobile A/C experience and is engineered and tested for dependable operation in demanding vehicle climate systems.

Key Features

• Rotary electronic heater valve for HVAC temperature control
• Electric valve operation with bypass style design
• Plastic construction for OE-style fit and function
• 3 connectors and 5 terminal pins
• Opening size: 0.79 in. / 20.17 mm
• Additional opening size: 0.88 in. / 22.35 mm
• Four Seasons 74933 replacement part for service and repair

Detailed Description

The Four Seasons 74933 heater control valve regulates heater core coolant flow to help maintain proper cabin temperature. It is a rotary electronic heater valve with electric operation and bypass-style routing, built for vehicles that require controlled HVAC coolant management. This part cross-references Dorman - HELP 74933 for the same application.

Compatible With 2016-2019 Chevrolet Volt and 2017-2018 Cadillac CT6, this heater valve supports accurate climate control performance in the vehicle’s heating circuit. If you are replacing a worn or malfunctioning heater valve on a Chevrolet Volt or Cadillac CT6, Four Seasons 74933 provides the correct fitment and connector configuration for those applications.

Common Problems This Part Can Address

• Inconsistent cabin heat output
• Heater core coolant flow that does not regulate correctly
• HVAC temperature changes that do not respond as expected
• Coolant bypass control issues in the heater circuit
• Fault codes or electrical concerns related to the heater valve assembly

Installation Notes and Tips

Verify connector count, terminal pin count, and opening dimensions before installation. Confirm the vehicle’s HVAC diagnosis before replacing the valve, and inspect related coolant hoses, electrical connectors, and control signals during service. This part is listed for 2016-2019 Chevrolet Volt and 2017-2018 Cadillac CT6 applications only.

Quality Assurance

Four Seasons states that its HVAC components are engineered and tested for long service life and supported by over 50 years of mobile A/C experience. The 74933 heater valve is built to meet the needs of select OEM-style repair applications.