Johnson Pump 36303 Ultima Automatic Switch
Free returns on all eligible orders
You have 30 days to request a return. All sale items are final sale.
The Johnson Pump 36303 Ultima Automatic Switch (SKU: 189-36303) is an electronic bilge pump switch designed for automatic operation. It uses patented Mirus field effect detector cells to sense disruptions caused by water and fluids—without moving parts, mercury, or exposed sensors.
Key Features
- Patented Mirus field effect detector cells detect disruptions caused by water and fluids
- Solid-state design with no moving parts
- Totally sealed detector cells never in direct contact with water
- Will not corrode and is not affected by oil or foreign debris
- No mercury and no exposed sensors help eliminate corrosion possibilities
- Automatic activation and deactivation levels designed for bilge use (activates at 2" fluid level and deactivates at 3/4" fluid level)
- 3-second delay helps prevent false starts from water sloshing
Product Compatibility
- Automatic control for marine bilge pumps (switch-to-pump automatic operation)
- Bilge pump systems that use a compatible electronic automatic switch setup
Product Details
- Brand/Model: Johnson Pump 36303 Ultima Automatic Switch
- SKU: 189-36303
- Type: Ultima Switch™ Electronic Automatic Switch
- Operation: Automatic bilge sensing and switching (activates at 2" fluid level; deactivates at 3/4" fluid level)
- Protection timing: 3-second delay to help prevent false starts
- Electrical rating (12V/24V): rated to handle pumps up to 20A at 12V or up to 10A at 24V
- Construction/sensing: sealed Mirus field effect detector cells; no moving parts; no mercury; no exposed sensors
- Switch behavior and switching is designed for use as an automatic switch component with compatible Johnson Pump marine bilge pump systems
Parts Desk Insights
Best Use Case: Great for replacing an existing Ultima-style electronic bilge switch when you want automatic water sensing with a solid-state, sealed detector design.
Common Issues: If your bilge pump doesn’t cycle as expected, confirm the wiring connections and that the switch is mounted/positioned correctly in the bilge. Also inspect for debris at mounting areas and verify the unit is clean and dry where it should be, since water slosh can trigger undesired cycling if the system is disturbed.
Related Products & Accessories
- Browse Bilge Pump Switches & Circuit Protection - If you’re sourcing additional control components for a complete automatic bilge pumping setup, explore the related bilge pump switch category.
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 1-3 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
Returns & Satisfaction Guarantee
We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.