Johnson Pump Ultima Automatic Bilge Pump Switch, Solid-State 20A 12V/24V Float Switch, Model 36303

The Johnson Pump Ultima Automatic Bilge Pump Switch (36303) is a solid-state float switch that automatically turns a bilge pump on and off based on rising and falling water levels, with no moving parts to jam, corrode, or wear out. Instead of a traditional mechanical float, the Ultima Switch uses patented Mirus field effect detector cells that generate micro-electrical fields to sense disruptions caused by water. These detector cells are fully sealed and never contact water directly, so they will not corrode and are unaffected by oil or foreign debris in the bilge.

The switch activates once fluid reaches a 2 inch level and deactivates once the level drops to 3/4 inch, with a built-in eight second delay that helps prevent false starts from sloshing water. It is rated to handle bilge pumps drawing up to 20 amps at either 12V or 24V, making it suitable for a wide range of boat electrical systems. A unique 3-way switch lets the operator disable the piezo alarm while keeping the warning LED illuminated, so the boat owner still gets a visual alert without the audible tone. With sealed solid-state electronics, no exposed sensors, and no mercury, the Johnson Ultima Switch is built to hold up in the harsh, wet marine environment where conventional float switches tend to fail.

Specifications

• Brand: Johnson Pump
• Manufacturer Part Number: 36303
• Type: Float Switch
• Pump Type: Switch
• Activation Level: 2 inches
• Deactivation Level: 3/4 inch
• Delay: 8 seconds
• Amperage Rating: Up to 20 amps
• Voltage: 12V or 24V
• Power Source: Battery powered
• Material: Copper
• Weight: 0.29375 pounds
• UPC: 729321363037

Fitment

Universal for 12V or 24V bilge pump systems rated up to 20 amps; not restricted to a specific make or model.

Replaces (OEM)

No OEM cross-reference numbers are specified for this part.

Frequently Asked Questions

What does the Johnson Pump 36303 Ultima switch do? The Johnson Pump Ultima Automatic Bilge Pump Switch (36303) automatically activates and deactivates a bilge pump based on fluid level, using patented field effect detector technology instead of a moving float.

At what water levels does the Ultima Switch turn the pump on and off? The switch activates once fluid reaches a 2 inch level and deactivates once the level drops to 3/4 inch, with an 8 second delay built in to prevent false starts from sloshing water.

How is this different from a traditional float switch? The Johnson Ultima Switch has no moving parts and uses sealed solid-state electronics with field effect detector cells rather than an exposed mechanical float, reducing the corrosion and jamming issues common with traditional float switches.

What amperage and voltage is the Ultima Switch rated for? Model 36303 is rated to handle bilge pumps drawing up to 20 amps at either 12V or 24V.

Does the sensor ever touch the water directly? No. The detector cells in the Johnson Ultima Switch are totally sealed and never contact water or fluid directly, which is why they will not corrode and are not affected by oil or debris.

Does the Ultima Switch have an alarm? Yes, it includes a piezo alarm along with a warning LED, and a unique 3-way switch lets you disable the audible alarm while keeping the LED lit for a visual-only warning.

Is there any mercury in this switch? No, the Johnson Pump Ultima Switch (36303) contains no mercury, consistent with its fully sealed solid-state design.

How much does the Johnson Ultima Switch weigh? The Johnson Pump 36303 Ultima Bilge Pump Switch weighs 0.29375 pounds.

Will this switch fit any bilge pump? The Ultima Switch is not tied to a specific bilge pump make or model; it can be combined with any bilge pump rated within its 20 amp, 12V/24V capacity.

Is the Ultima Switch prone to false triggering from wave action? The 36303 switch includes an eight second activation delay specifically to help prevent false starts caused by sloshing or wave-induced water movement.