Engine
Engine 38HP — Volvo Penta D2-40 wiring diagram
Volvo Penta D2-40 family. The D2-40F manual specifies 12 V, a 2.0 kW starter and 115 A alternator. Modeled 180 A cranking and 360 A surge are estimates; match the engine suffix, panel and electrically isolated drive arrangement.
- Continuous draw
- 180 A
- Rated output
- 115 A
- Surge current
- 360 A
Wiring diagram
How the D2-40 38HP is wired.
Open this example in Crimp to use your own parts and cable lengths. Review the assumptions and installation notes as you adapt the circuit.
Cable sizing for this example
Use the diagram as a starting point for your installation. Replace the example equipment and cable lengths with your own, and check the connections against your exact model's instructions.
3 m one way
12 V system
- Wire
- 120 mm² · 4/0 AWG
- Example fuse
- 250 A
- Cranking current
- 180 A
- Voltage drop
- 1.3%
Sized against ABYC E-11. The cranking current is what the starter draws. ABYC E-11 doesn't require a fuse on a cranking-motor conductor, so the fuse shown is the usual cranking-rated (Class T) choice, sized to hold the crank without nuisance tripping — it isn't there to protect the wire. The length is one way; voltage drop includes an equal-length return.
Run-length and manufacturer assumptions
The editable example uses 3.048 m (10 ft) runs unless a shorter run is stated. Metric overviews round these to 3 m. Adapt the parts and lengths to your installation before choosing cable and protection.
Supporting parts
- 6.1 m total of 120 mm² (4/0 AWG) marine cable
- Terminations for 120 mm² cable, matched to the equipment's screw terminals, leads or studs
- 250 A cranking-rated (Class T) fuse at the battery
- Heat-shrink, strain relief and terminal boots sized to the cable
Check stud sizes, fuse type, run length and how warm the space gets against the gear you actually have before you order.
Installation notes
Before you install.
Open a question for model-specific guidance and sources.
Reviewed against manufacturer family documentation (rev. 7748803 French — October 2020), checked 2026-10-01. Exact variant details still require confirmation. Manufacturer documentation →
Engine and edition
The downloaded Volvo D1/D2 operator manual explicitly covers D2-40F. Its electrical table specifies 12 V, a 70 Ah starter battery, a 14 V/115 A alternator and approximately 2.0 kW starter output. The unsuffixed catalog entry does not establish whether a particular engine is B, F or another production revision; confirm the product and serial numbers before selecting harness parts.
What the terminals mean
`Starter` represents the high-current starter supply, `Alt B+` the alternator charging output, and `Block GND` the intended negative return on an earth-return installation. They are functional drawing ports, not three interchangeable physical studs. Trace any factory link between alternator B+ and the starter battery stud before changing it; do not duplicate or remove that link without accounting for the original harness.
Controls and protection
The engine management/control system operates the start, stop and alarm functions. The manual identifies a blade fuse that interrupts an overloaded engine-control supply; investigate the cause if instruments or starting cease, rather than bypassing it. Its rating must be checked on the fitted harness. The manual separates the engine supply from accessory supplies and illustrates how return wiring can defeat electrical isolation of the drive. Retain the original engine-control protection and alarm connections. Do not interpret a missing alarm or panel port in the drawing as permission to omit that equipment.
Checks and model limits
Use the documented engine stop control before opening the main battery switch; this edition requires a 30-second delay after switching off the control system so engine data can be stored. A battery switch must not interrupt the charging circuit while the alternator is running. Keep starter and return cables short and assess voltage at the starter during cranking. The catalog 180 A cranking and 360 A inrush are estimates, not guaranteed maxima from Volvo. The simplified block-ground symbol does not authorize bonding an insulated saildrive or transmission to battery negative.
Source: manufacturer document — shutdown printed pp. 38–39 (PDF 40–41), electrical maintenance pp. 67–72 (PDF 69–74), D2-40F identity p. 83 (PDF 85), electrical ratings p. 88 (PDF 90). Legacy copies hosted outside the manufacturer site are manufacturer-authored archive documents; the review date does not make them current installation instructions.
Fit check
Connect it to the rest of your system.
Describe your setup to draft a system with D2-40 connected. Review the selected parts and cable lengths, then edit the diagram in Crimp.
The model only picks parts and draws the connections. Every wire size and fuse rating still comes from Crimp's own sizing, never from the model.
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Technical reference
Specifications and terminal map.
Check the model, ratings and connection points against your own unit before choosing installation hardware.
Catalog specification
Volvo Penta D2-40 family. The D2-40F manual specifies 12 V, a 2.0 kW starter and 115 A alternator. Modeled 180 A cranking and 360 A surge are estimates; match the engine suffix, panel and electrically isolated drive arrangement.
- Continuous draw
- 180 A
- Rated output
- 115 A
- Surge current
- 360 A
Terminal map
Catalog connection points, current direction and planning limits. Check the manufacturer's pinout and connector ratings before installation.
Starter
positive · input
Alt B+
positive · output
Block GND
ground · bidi
Sources and sizing method
Equipment specifications. Model details, ratings and terminal roles come from the catalog. Check your unit’s label and current manufacturer documentation for its exact revision.
Example sizing. Sized against ABYC E-11. Boats built to UK or EU rules answer to ISO 13297 — check these figures against it before you build. Results use the example current and run length shown above. Set your actual equipment, lengths and installation conditions in Crimp before choosing hardware.
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Plan your installation with D2-40 38HP.
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