Standard Ignition SS-591 Diesel Glow Plug Relay

Diesel Glow Plug Relay for 1979-1985 GM Applications

Standard Ignition SS-591 is a 12-volt diesel glow plug relay built for direct replacement service on a wide range of Buick, Chevrolet, GMC, Cadillac, Oldsmobile, and Pontiac applications. It uses a 100-amp rating, male connectors, and a stud-and-blade terminal layout to support reliable glow plug circuit control in older diesel-equipped vehicles.

Key Features

• 12-volt diesel glow plug relay with a 100 A amperage rating
• Male connector design with 2 round connectors
• 4 male terminals with stud and blade terminal type
• Includes mounting bracket for installation support
• Built with heavy-duty copper contacts and high-grade electrical materials
• Pure copper windings and copper battery terminal studs help reduce resistance
• Polyester-insulated magnet wire and cadmium-plated copper discs support lower voltage drop

Product Details

The Standard Ignition SS-591 is engineered for diesel starting and charging system service where dependable relay operation matters. Its internal copper contact design helps limit arcing, while the copper winding construction supports a stronger magnetic field for consistent electrical switching. The relay’s materials are selected to reduce voltage loss and improve current flow, which is important in demanding underhood conditions. This part cross-references Bosch 16136 for the same application. Standard Ignition SS-591 is a practical choice for restoring glow plug relay function on classic GM diesel platforms, including Chevrolet C10, GMC C1500, and Oldsmobile Delta 88 applications.

Common Problems This Part Can Help Solve

• Hard starting on diesel engines caused by weak glow plug relay operation
• Intermittent glow plug activation during cold starts
• Voltage drop in the glow plug circuit
• Electrical arcing that shortens relay service life
• Relay failure from worn contacts or high-resistance connections

Installation Notes and Fitment

Compatible With 1979-1985 Buick Regal, 1980-1985 Chevrolet C10, 1982-1985 Chevrolet C20, 1982-1985 Chevrolet C30, 1983-1985 Chevrolet G20, 1983-1985 Chevrolet G30, 1985 Chevrolet K10, 1985 Chevrolet K20, 1985 Chevrolet K30, 1979-1984 Oldsmobile 98, and additional listed Buick, Cadillac, Chevrolet, GMC, Oldsmobile, and Pontiac diesel applications. Fitment also includes 1982-1984 Chevrolet K10, K20, K30, K5 Blazer, P20, and P30, plus 1980-1984 GMC C1500, C2500, C3500, G2500, G3500, K1500, K2500, K3500, P2500, and P3500. Verify connector style, terminal layout, and mounting location before installation; some applications note solenoid-type or 2-blade terminal requirements. The included bracket supports mounting, and the relay should be matched to the vehicle’s 12-volt electrical system.

Quality Assurance

Standard Ignition manufactures ignition and starting system components with controlled production processes and high-grade materials from component to finished part. SS-591 is built to support long service life in demanding electrical environments.