Volvo Penta 24V Relay 3171420 | OEM Electrical System

Part Information

• Part Number: 3171420
• Brand: Volvo Penta
• Official Product Type: Relay — 24V Electrical System
• Supersedes: 4786690, 21072016, 20374662
• Replaced By: No confirmed Volvo Penta supersession on record (verify by serial number)
• Diagram Position: Object Key 10 — D5A-B TA / Cables and Fuses (also used in fuse and relay holders, terminal boxes, and engine wiring harness assemblies across multiple engine families)

Overview

The Volvo Penta 3171420 is a genuine OEM 24V relay used across a wide range of Volvo Penta marine and industrial engine electrical systems. It appears in fuse and relay holders, terminal boxes, and engine wiring harness assemblies, and is the current replacement for earlier references 4786690, 21072016, and 20374662. Because the same relay is used across many different electrical assemblies and engine families, matching by the exact Volvo Penta electrical schematic and engine serial number is the most reliable way to confirm correct fitment.

Compatible Applications

• Volvo Penta D3-110I-B / C, D3-130A-A, D3-130I-C, D3-150I-H, D3-170I-H, D3-200I-H, D3-220I-G / H
• Volvo Penta D4-150A-G, D4-230A-G, D4-260A / D / I (multiple generations), D4-270A-G, D4-300A / D / I (multiple generations)
• Volvo Penta D6-330A / D, D6-350A, D6-370A / D (multiple generations)
• Volvo Penta D8A2-A MP, D8A3-A MP
• Volvo Penta D11A-C-MP, D11A-D-MP
• Volvo Penta D13B-A MP, D13C2-B MP
• Volvo Penta TAD, TAMD, TWD, and MD series applications (confirm by schematic and serial number)

Relay fitment varies by harness layout, ECU version, and production break. Always confirm against the exact Volvo Penta electrical schematic and engine serial number before ordering — relays can look similar across different assemblies but serve different switching functions.

Serial Number Requirements

Always confirm your engine model, serial number, and the exact Volvo Penta electrical-system diagram before ordering. Relays can appear identical across different fuse holders, relay boxes, and harness assemblies — schematic confirmation is more reliable than visual comparison alone.

System

Electrical System — Fuse & Relay Holder / Terminal Box / Engine Wiring Harness

Dimensions & Weight

• Voltage: 24V
• Weight: Approximately 0.03 kg
• Relay dimensions per Volvo Penta electrical system specification

When This Part Needs Replacement

Replace the relay if any of the following apply:

• Relay fails to switch or does not energize correctly
• Intermittent electrical operation in the associated circuit
• Heat damage, corrosion, or burnt terminals
• Relay identified as faulty during electrical system diagnosis

It is also worth inspecting the relay socket and surrounding harness condition whenever related fuse-holder or relay-box components are already apart.

Installation Notes

Confirm the exact relay position in the applicable Volvo Penta electrical schematic before installation. Compare the removed relay carefully against the replacement part — pin configuration, coil voltage, and switching rating must match. Inspect the relay socket and terminals for corrosion or damage before fitting the new relay.

Technical FAQ

Q: What earlier part numbers does 3171420 replace?
A: 3171420 supersedes earlier Volvo Penta references 4786690, 21072016, and 20374662. Always order by the current active OEM number.

Q: Is this relay used on D3 engines only?
A: No — 3171420 is used across a wide range of Volvo Penta marine and industrial engine families including D3, D4, D5, D6, D8, D11, D13, TAD, TAMD, and MD series. The exact application depends on the harness layout and electrical schematic for your specific engine.

Q: How do I confirm this is the right relay for my engine?
A: Match your engine model and serial number to the applicable Volvo Penta electrical-system diagram and confirm the relay position by object key or circuit reference. Visual comparison alone is not sufficient — relays can look identical but have different switching specifications.

Q: Has this relay been superseded by a newer number?
A: 3171420 is the current active Volvo Penta OEM number. Some third-party catalog listings reference a newer number, but this has not been confirmed as an official Volvo Penta supersession. Verify against your engine serial number and the current Volvo Penta parts diagram before ordering any substitute.

Parts Desk Insights

The most common mistake with relay orders is matching by pin style or housing size rather than by the electrical schematic. The same relay housing can appear in many different Volvo Penta assemblies with different switching functions — the diagram is the only reliable way to confirm the right part. It’s also worth noting that some third-party catalog listings show a newer number as a replacement for 3171420, but this has not been confirmed as an official Volvo Penta supersession — always verify against the current Volvo Penta parts diagram and engine serial number before substituting.