Sierra 18-5840 Marine Starter Solenoid, Replaces Prestolite SAW4201, SAW4207, SAW4210, 15-79

The Sierra 18-5840 is a 12-volt marine starter solenoid built with a steel housing and copper contacts for reliable current transfer in the engine bay. It is configured as a grounded 12-volt unit with an 85 amp continuous rating at 12 VDC, making it suitable for use as a lever-switch style solenoid in starter circuits that call for this rating and configuration. The steel housing resists the vibration and heat exposure typical of an engine compartment, while the copper contact construction is chosen for consistent conductivity over repeated engagement cycles.

This solenoid is a direct replacement for the listed Prestolite cross-reference numbers, so it can be used to service or replace an original starter solenoid on applications that originally used one of those Prestolite parts. It ships as a compact unit measuring 3 x 6 x 7.5 inches and weighing 0.79 pounds, sized to fit into the same mounting space as the OEM solenoid it replaces.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-5840
• Type: Lever switch / starter solenoid
• Housing Material: Steel
• Contacts: Copper
• Voltage: 12 Volts, grounded
• Continuous Rating: 85 amp @ 12 VDC
• Weight: 0.79 pounds
• Dimensions: 3 x 6 x 7.5 inches
• OEM Cross Reference: Prestolite SAW4201, SAW4207, SAW4210, 15-79

Fitment

• Fits applications originally equipped with a Prestolite SAW4201, SAW4207, SAW4210, or 15-79 starter solenoid.

Replaces (OEM)

• Prestolite SAW4201
• Prestolite SAW4207
• Prestolite SAW4210
• Prestolite 15-79

Frequently Asked Questions

What voltage and amperage is the Sierra 18-5840 rated for? The Sierra 18-5840 is a 12-volt, grounded starter solenoid with an 85 amp continuous rating at 12 VDC.

Is the Sierra 18-5840 a direct replacement for a Prestolite solenoid? Yes, the 18-5840 replaces the Prestolite SAW4201, SAW4207, SAW4210, and 15-79 starter solenoids.

What are the dimensions of this solenoid? The Sierra 18-5840 measures 3 x 6 x 7.5 inches.

How much does the Sierra 18-5840 weigh? It weighs 0.79 pounds.

What is the housing made of? The 18-5840 uses a steel housing with copper contacts, which stands up to the heat and vibration of an engine compartment.

Is this solenoid grounded or insulated? The Sierra 18-5840 is a grounded 12-volt solenoid, not an insulated design.

What type of switch is the 18-5840? It is built as a lever switch style starter solenoid with copper contacts for consistent conductivity.

Will the 18-5840 fit an application that used a Prestolite SAW4207? Yes, the Sierra 18-5840 directly cross-references to the Prestolite SAW4207, along with the SAW4201, SAW4210, and 15-79.

Does the 18-5840 include mounting hardware? The listing covers the Sierra 18-5840 solenoid unit itself; check your original hardware for reuse during installation.

Is the Sierra 18-5840 genuine or aftermarket? The 18-5840 is a genuine Sierra part manufactured to replace the specified Prestolite OEM solenoids.