Dorman 904-623 HVAC Pressure Switch

Dorman 904-623 HVAC Pressure Switch

Restore A/C system control with this Dorman HVAC pressure switch, part number 904-623. It is a specific-fit replacement for vehicles using R134A refrigerant and a screw-on, 7/16-20 threaded transducer-style switch with a circular female connector.

When the original pressure switch has corroded terminals or a damaged connector, this replacement helps bring the air conditioning system back online. It is a direct replacement for select Buick, Cadillac, and Oldsmobile applications, including 1986-1993 Cadillac DeVille, 1986-1993 Cadillac Eldorado, and 1986-1993 Cadillac Fleetwood.

Key Features

• Brand: Dorman
• Part number: 904-623
• Specific-fit HVAC pressure switch for select A/C systems
• Works with R134A refrigerant systems
• Pressure limits: closed at 10 and open at 20
• Maximum pressure reading: 350 PSI
• Metal housing with silver finish
• Black circular female connector with 2 male blade terminals
• Screw-on mount with 7/16-20 thread diameter
• 13-volt, 4-amp rating

Detailed Description

This Dorman A/C pressure switch is built as a direct replacement for the original transducer switch used in select GM applications. It addresses common failure points such as corroded terminals, broken connectors, and switch-related A/C shutdowns. The design uses a metal housing, circular connector shape, and blade terminals to match the original connection style on supported vehicles. This part number 904-623 is listed for fitment on 1986-1993 Buick Riviera, 1987-1993 Cadillac DeVille, 1986-1993 Cadillac Eldorado, 1986-1993 Cadillac Fleetwood, 1986-1993 Cadillac Seville, 1987-1992 Cadillac Brougham, 1986-1992 Oldsmobile Toronado, and 1988-1991 Buick Reatta.

This part cross-references Four Seasons 36668 for the same application.

What It Helps Fix

• A/C compressor cycling problems caused by a faulty pressure switch
• Air conditioning that stops working because of damaged switch terminals
• Electrical connection issues from a broken original connector
• Pressure-signal faults in R134A-equipped HVAC systems
• Intermittent A/C operation on select Buick, Cadillac, and Oldsmobile models

Installation Notes and Tips

Verify the connector shape, thread size, refrigerant type, and pressure specifications before installation. This is a screw-on switch with a 7/16-20 thread diameter and a circular female connector, so matching the original part style is important for proper fitment. Confirm vehicle application by year and model before ordering, especially on Cadillac DeVille, Cadillac Eldorado, and Buick Riviera applications.

Quality Assurance

Dorman replacement parts are built to restore original function on specific applications. This HVAC pressure switch is intended as a direct replacement for the factory-style component on supported vehicles.