Low Oil Pressure Sender Sensor Switch – Fits MerCruiser 4.3 5.0 5.7 (Replaces 87-805605A1, OP22900, 97767)
Low Oil Pressure Sender Sensor Switch – Fits MerCruiser 4.3 5.0 5.7 (Replaces 87-805605A1, OP22900, 97767) is backordered and will ship as soon as it is back in stock.
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Low Oil Pressure Sender Sensor Switch – Fits MerCruiser 4.3 5.0 5.7...
Low Oil Pressure Sender Sensor Switch – Fits MerCruiser 4.3 5.0 5.7 (Replaces 87-805605A1, OP22900, 97767) is backordered and will ship as soon as it is back in stock.
Product Details
This Low Oil Pressure Sender Sensor Switch is designed for MerCruiser 4.3, 5.0, and 5.7 engines. It monitors oil pressure and activates the alarm system or shuts off the electric fuel pump when pressure drops to unsafe levels, protecting your engine from catastrophic damage.
This aftermarket replacement directly substitutes for MerCruiser 87-805605A1, Sierra OP22900, Crusader 97767, and Marine Power 457045.
- Senses low oil pressure at 6 PSI threshold
- Terminal type: 10-32 stud; Thread size: 1/8-27
- Shuts off electric fuel pump to prevent engine damage
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| MerCruiser | 87-805605A1 |
| Sierra | OP22900 |
| Crusader | 97767 |
| Marine Power | 457045 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
| Brand | Model |
|---|---|
| MerCruiser | 4.3 |
| MerCruiser | 5.0 |
| MerCruiser | 5.7 |
Technical Specs
- Pressure Threshold
- 6 PSI
- Terminal Type
- 10-32 stud
- Thread Size
- 1/8-27
- Function
- Low oil pressure sensing / electric fuel pump shutoff
What's in the Box
- 1 × Low Oil Pressure Sender Sensor Switch
Installation Notes
- Disconnect the battery negative terminal and relieve fuel system pressure before beginning work.
- Locate the existing oil pressure sender on your engine block or oil filter housing.
- Disconnect the wiring terminal from the old sender.
- Use an appropriately sized wrench to unthread the old sender; have a rag ready to catch residual oil.
- Apply thread sealant suitable for oil applications to the threads of the new sender.
- Hand-thread the new sender into the port, then tighten to manufacturer torque specification (typically 10–15 ft-lbs).
- Reconnect the wiring terminal to the 10-32 stud on the new sender.
- Reconnect the battery, start the engine, and verify the oil pressure warning lamp or alarm functions correctly.
Troubleshooting & FAQ
Will this fit my MerCruiser engine?
This sender is compatible with MerCruiser 4.3, 5.0, and 5.7 models. Verify your original part number (87-805605A1) and thread size (1/8-27) before ordering.
What does a low oil pressure sender do?
It monitors engine oil pressure and triggers an alarm or shuts off the electric fuel pump when pressure falls below 6 PSI, preventing engine damage from lubrication failure.
How do I know if my sender is failing?
Common symptoms include intermittent or constant oil pressure warning lights, false alarms at idle, or no warning when pressure actually drops. Test with a mechanical gauge to confirm.
Do I need thread sealant?
Yes. Use a thread sealant rated for oil and fuel applications to prevent leaks and ensure an accurate pressure reading.
What is the torque specification?
Typical torque is 10–15 ft-lbs. Consult your engine service manual for exact specifications to avoid stripping the port or damaging the sender.
Can I test the sender before installation?
Yes. Use a bench test with compressed air and a pressure gauge set to 6 PSI to verify the switch activates at the correct threshold.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.
Shipping speed & cost
We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
Warranty & returns
Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.
Safety & Important Info
- Verify images/specifications against your original part. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement, not an OEM component.
- Professional installation is recommended for safety and performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
- Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
- Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.
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