Mercury MerCruiser Quicksilver Oil Pressure Switch 8M0070108
Free returns on all eligible orders
You have 30 days to request a return. All sale items are final sale.
Mercury MerCruiser Oil Pressure Switch
Part Number: 8M0070108 | OEM Prefix: 87-8M0070108 | GTIN: 745061546042
Brand: Mercury / MerCruiser | Type: Engine Oil Pressure Switch
Genuine Mercury MerCruiser OEM oil pressure switch for selected MerCruiser gasoline engines. This switch monitors engine oil pressure as part of the engine’s warning and protection circuitry. Supersedes earlier Mercury switch 864252.
Compatible Applications
- Selected MerCruiser gasoline inboard and sterndrive engines — verify by engine model and serial number
- Installations where 8M0070108 is shown in the engine oil-system diagram alongside a separate oil-pressure sender (such as 8M0068784)
This switch appears across multiple MerCruiser engine configurations. Confirm the exact engine model, serial number, and diagram position before ordering. Do not order based on engine displacement alone.
Switch vs. Sender: Which Do You Need?
8M0070108 is the oil-pressure switch for the engine warning/protection circuit — it is a separate component from the oil-pressure sender used to drive the oil-pressure gauge. Mercury diagrams list these as distinct parts. If you need the gauge sender, see the Mercury MerCruiser Oil Pressure Sender 8M0068784.
When This Switch Needs Replacement
Replace the oil-pressure switch when diagnostic testing confirms incorrect switching behavior, when the warning circuit does not respond properly to changing oil pressure, or when the switch body or electrical connection is damaged or corroded.
Installation Notes
Disconnect battery power before beginning service. Confirm the replacement switch is being installed in the correct oil-pressure port — not the sender port. Inspect the wiring terminal, connector, fitting, and surrounding area for oil leakage or damage before installation. Follow the applicable Mercury MerCruiser service procedure for installation and system verification.
Related Products
- Mercury MerCruiser Quicksilver Oil Pressure Sender 8M0068784 (gauge sender — separate component)
Alternate & Superseded Part Numbers
- Current OEM: 8M0070108
- OEM prefix: 87-8M0070108
- Supersedes: 864252
- GTIN: 745061546042
Parts Desk Insights
The most common customer confusion with 8M0070108 is ordering the switch when they actually need the oil-pressure sender (8M0068784), or vice versa. The switch activates the warning system; the sender drives the gauge. Both parts are installed on many of the same engines and are located in the same area. Always have the customer confirm which port they are servicing and verify using the Mercury engine diagram for their specific model and serial number before ordering.
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.