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Most new, unused items may be returned within 7 days of delivery, subject to our Returns Policy. A 20% processing/restocking fee may apply for returns that are not the result of our error. Original shipping charges are non-refundable.
If the return is due to our mistake (incorrect or defective item), we will cover the return shipping cost and issue a full refund.
EU customers are entitled to a 14-day cooling-off period in accordance with applicable consumer protection regulations. Certain exclusions may apply.
Refunds are issued after the returned item is received and inspected. Processing times may vary depending on shipping transit and payment provider handling, but most refunds are completed promptly.
To request a return, please contact us at info@jlm-marine.com with your order number for return authorization. For full terms, conditions, and exclusions, please refer to our complete Returns & Refunds Policy page.
This aftermarket oil pressure gauge sender replaces MerCruiser / Mercury 815425 (current catalogue 8M0068784). It threads into an oil-gallery boss and drives an electric oil pressure gauge. It is not an on/off warning-light switch.
Match this part in this order:
1. OEM number on the removed sender or in your parts catalog (815425, 815425T, 8M0068784, Volvo Penta 3857532 / 3853800, OMC 982650, or Crusader 700425)
2. Terminal and thread — 10-32 stud terminal and 1/8-27 male pipe thread
3. Function — electric gauge sender, not a blade-terminal light switch
Identify the form from the product images: yellow-zinc bell-shaped body, 10-32 stud with nut, washer and insulator, and male pipe threads at the opposite end. If your original has a single blade terminal (warning-light switch) rather than a 10-32 stud, it is a different component.
Use this table to confirm equivalent part numbers. Mercury also catalogs 815425T, 90806, and 90806A1 in the same supersession chain to 8M0068784.
| Type | Brand | Part Number | Notes |
|---|---|---|---|
| OEM | Mercury MerCruiser | 815425 | Primary reference; superseded by 8M0068784 |
| OEM | Mercury MerCruiser | 8M0068784 | Current sender; also supersedes 815425T and 90806 |
| OEM | Volvo Penta | 3857532 | Volvo Penta equivalent; also listed as 3853800 |
| OEM | OMC Cobra | 982650 | OMC equivalent (also cataloged 0982650) |
| OEM | Crusader | 700425 | Crusader inboard equivalent |
| Aftermarket | Sierra | 18-5899 | Direct aftermarket replacement |
Part numbers are listed for identification only. This is an aftermarket part manufactured by JLM Marine and is not sold as a genuine Mercury, Volvo Penta, OMC, or Crusader component.
Confirm your engine model and original part number before ordering. On MerCruiser sterndrive and inboard engines, the identification plate and serial number are on the engine itself — typically on the cylinder block or flame-arrestor cover — not on an outboard transom bracket. Cross-check with the Mercury Parts Diagrams for MerCruiser. On Volvo Penta, the plate is typically on the cylinder block or flywheel housing.
| Brand | Application | Notes |
|---|---|---|
| MerCruiser | Sterndrive and inboard gasoline engines calling for 815425 / 8M0068784 | 10-32 stud gauge sender |
| Volvo Penta | Sterndrive / outdrive gasoline engines calling for 3857532 or 3853800 | 10-32 stud gauge sender |
| OMC Cobra | Sterndrive gasoline engines calling for 982650, 3853800, or 3857532 | 10-32 stud gauge sender |
| Crusader | Inboards calling for 700425 | 10-32 stud gauge sender |
| Specification | Value |
|---|---|
| Part type | Electric oil pressure gauge sender |
| Primary OEM number | 815425 |
| Thread | 1/8-27 male pipe thread |
| Terminal | 10-32 threaded stud |
| Function | Drives an electric oil pressure gauge (not a warning-light switch) |
| Form | Yellow-zinc bell body with stud nut, washer, and insulator |
Allow the engine to cool fully. Disconnect the battery negative cable before working on the gauge circuit.
Remove the gauge wire from the 10-32 stud. Unscrew the old sender and compare its thread and terminal to this 1/8-27 / 10-32 unit. Do not force a mismatched thread.
Thread the new sender in by hand, then tighten snugly on the body — do not over-torque or damage the insulator. Follow the engine service manual for thread sealant practice.
Reconnect the gauge wire under the 10-32 nut with the washer in place. Restore the battery, start the engine, and confirm the gauge moves with oil pressure and that there are no oil leaks at the port.
Note: Professional installation is recommended to ensure safety and optimal performance.
This is an aftermarket JLM Marine replacement matched to MerCruiser 815425. It is not a genuine Mercury, Volvo Penta, OMC, or Crusader part.
No. This is a variable-resistance sender for an electric oil pressure gauge. A blade-terminal light switch (for example Sierra 18-5894 applications) is a different part.
Match the OEM number on the removed sender and the gauge it feeds. Do not assume a psi or ohm value from a generic listing — confirm the gauge scale against your instrument cluster.
Recheck the 10-32 stud connection and ground through the engine block, confirm actual oil pressure, and verify you replaced a gauge sender rather than a warning switch. Persistent faults can be wiring, the gauge, or a real lubrication issue.
We can ship to virtually any address in the world with free shipping available for most regions.
For our typical US and Canadian customers , our shipping timeframes are as follows:
When you place an order, we will estimate shipping and delivery dates for you based on the availability of your items and the shipping options you choose. Depending on the shipping provider you choose, shipping date estimates may appear on the shipping quotes page.
Please also note that the shipping rates for many items we sell are weight-based. The weight of any such item can be found on its detail page. To reflect the policies of the shipping companies we use, all weights will be rounded up to the next full pound.
Founded in 2002, JLM Marine has established itself as a dedicated manufacturer of high-quality marine parts, based in China. Our commitment to excellence in manufacturing has earned us the trust of top marine brands globally.
As a direct supplier, we bypass intermediaries, which allows us to offer competitive prices without compromising on quality. This approach not only supports cost-efficiency but also ensures that our customers receive the best value directly from the source.
We are excited to expand our reach through retail channels, bringing our expertise and commitment to quality directly to boat owners and enthusiasts worldwide.
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