Oil Pressure Sender Sensor 8M0068784 815425T for MerCruiser Volvo Penta OMC Mercury 3.0 4.3 5.0 5.7 7.4 Sierra 18-5899 — United Kingdom Local Warehouse
Oil Pressure Sender Sensor 8M0068784 815425T for MerCruiser Volvo Penta OMC Mercury 3.0 4.3 5.0 5.7 7.4 Sierra 18-5899 — United Kingdom Local Warehouse
Product Overview
Replacement oil pressure sensor for MerCruiser, Volvo Penta and OMC petrol engines, the electric sender that drives the dash gauge, 1/8 in NPT thread, 80 psi working range, 10-32 stud terminal, supplied as one unit. It replaces 8M0068784, 34623, 815425, 815425T, 90806, 3857532 and 172127, and matches Sierra 18-5899. Dispatched from our United Kingdom local warehouse.
Three things sit in the oil pressure circuit and only one of them is usually at fault: the sender, the gauge on the dash, and the length of wiring between them. Swapping parts at random gets expensive, so the table further down walks through which one the symptom actually points at.
The sender itself is a variable resistor. As pressure rises, its resistance falls and the gauge needle moves. Nothing about that is digital, so a corroded terminal or a damp connector gives exactly the same reading on the dash as a failed sender.
Specifications
| Specification | Detail |
|---|---|
| Condition | New / New with tags |
| Type | Electric oil pressure sender |
| Thread | 1/8 in NPT (3.2 mm, 27 TPI) |
| Pressure Range | 80 psi |
| Terminal | 10-32 stud, single |
| Body Height | 7.7 cm (3.0 in) |
| Finish | Gold passivated metal |
| Gauge Match | 80 psi electric oil pressure gauge |
| Quantity | 1 sender |
OEM Cross Reference
| Brand | OEM Part Numbers |
|---|---|
| MerCruiser | 8M0068784, 34623, 815425 |
| MerCruiser | 815425T, 90806, 90806A1 |
| Volvo Penta | 3857532 |
| OMC | 172127, 3853800, 3857532, 982650 |
| Sierra | 18-5899 |
Compatible Engines
| Engine | Displacement | CID |
|---|---|---|
| MerCruiser inline 4 | 3.0L | 181 CID |
| MerCruiser V6 | 4.3L | 262 CID |
| MerCruiser V8 | 5.0L and 5.7L | 305 to 350 CID |
| MerCruiser V8 | 6.2L | 377 CID |
| MerCruiser V8 | 7.4L and 8.2L | 454 to 502 CID |
| MerCruiser V8 | 8.8L and 9.4L | 502 to 572 CID |
| Mercury Marine | Petrol inboard and sterndrive | Same thread and range |
| Volvo Penta | Petrol inboard and sterndrive | Same thread and range |
| OMC | Petrol inboard and sterndrive | Same thread and range |
| Crusader and Pleasurecraft | Petrol inboard | Same thread and range |
What's Included
| Component | Qty |
|---|---|
| Oil pressure sender, 1/8 in NPT, 80 psi | 1 |
Sender, Gauge or Wiring
| Dash Reading | Likely Cause | Test Before Ordering |
|---|---|---|
| Needle dead at zero, ignition on, engine off | Sender or the wire to it | Earth the sender wire, needle should swing to full scale |
| Needle swings when wire is earthed but not connected | Sender failed | This sender is the fix |
| Needle does not move even when the wire is earthed | Gauge or dash wiring | A sender will not help, chase the gauge circuit |
| Needle reads low only when the engine is hot | Sender drifting with temperature | Common on 10 year old units, replace the sender |
| Needle jumps when the boat is underway | Loose terminal or chafed wire | Inspect the run to the dash first |
| Alarm sounds but the gauge reads normal | Second sender or the alarm switch | Some engines carry two, check both |
Fitting Notes
| Step | Action |
|---|---|
| 1 | Read the gauge face, this unit is the 80 psi electric sender, not the 100 psi version and not a mechanical capillary |
| 2 | Earth the sender wire on the block with the ignition on and watch the needle, this separates a wiring fault from a sender fault |
| 3 | Confirm actual pressure with a mechanical gauge on the same port before spending money on a sender |
| 4 | Clean the port thread on the brass or alloy housing, dried sealant in a taper thread gives a false tight feel |
| 5 | Sealant on the upper threads only, keep the first two threads clean so the oilway stays open |
| 6 | Tighten on the hex body, never on the plastic terminal housing |
| 7 | Check the ring terminal is bright metal, damp engine bays corrode them faster than the sender fails |
| 8 | Run from cold to hot and watch the needle move smoothly through the range before the boat goes back out |
Condition & Warranty
| Item | Detail |
|---|---|
| Condition | New / New with tags |
| Warranty | Standard |
| Packaging | Boxed |
Shipping from the United Kingdom
| Destination | Warehouse | Note |
|---|---|---|
| United Kingdom | United Kingdom local warehouse | Domestic delivery, no import duty |
| Ireland | United Kingdom local warehouse | Customs may apply |
| EU destinations | United Kingdom local warehouse | Customs and import VAT may apply |
Before You Buy
- Read the gauge face, this unit is the 80 psi electric sender, not the 100 psi version and not a mechanical capillary
- Earth the sender wire on the block first, it separates a wiring fault from a sender fault
- Confirm actual pressure with a mechanical gauge before spending money on a sender
- Clean the port thread and keep sealant off the first two threads
- This is the sender only, the gauge, the alarm switch and the dash wiring are not included
- 30-Day Easy Returns
- Ships from our United Kingdom local warehouse
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