DB Electrical 11SI Marine Alternator 95A 12V — 6-Groove Pulley CW Direct-Fit Replacement

The DB Electrical 400-12300 is a direct-fit 12‑volt, 95‑amp 11SI marine alternator engineered to replace common OEM units for Indmar, Delco and other marine engines.

This compact alternator is designed for marine charging systems that require a 6‑groove pulley (63mm OD) and a clockwise rotation. It matches mounting dimensions and electrical terminals used on many 11SI style units so you can swap it into boats and marine applications without modifying the engine. Before ordering, confirm the part number, mounting ear holes and pulley specification on your existing alternator to ensure compatibility.

Will this alternator fit my boat engine?

Check five key points on your current alternator: mounting ear type, pulley groove count and diameter, rotation direction, terminal styles, and amperage. The DB Electrical 400-12300 replicates common 11SI measurements and terminal positions used by multiple OEMs, making it a direct replacement when those details match.

• Mount: 2" mounting foot with one threaded M8‑1.25 and one 10.1mm unthreaded hole
• Pulley: 6‑groove pulley, 63mm outside diameter
• Rotation: clockwise (CW)
• Terminals: B+ M8‑1.25 plus spade P, L, IG and S terminals
• Output: 95 amps at 12 volts, 11SI footprint

How reliable is this alternator in marine conditions?

The unit is built with rugged components and an internal regulator to handle the typical demands of marine electrical systems. While not a sealed OEM part, its construction and cooling fan design aim to provide steady charging under continuous use.

• Internal IR regulator for stable voltage control
• IF fan type for consistent airflow and heat dissipation
• Robust housing materials selected for durability
• Designed for heavy electrical loads common in marine environments

What electrical and mechanical connections does it use?

This alternator uses the standard 11SI-style connectors so wire-up is familiar to most marine technicians. It includes a threaded B+ stud and four labeled spade terminals for lamp, charge sense and ignition signals.

• B+ terminal: M8‑1.25 threaded stud for battery cable
• P, L, IG, S: spade terminals for warning lamp, field, ignition and sense circuits
• Clocking: 12 o'clock position for pulley orientation
• Pulley class: S6 compatible with 6‑rib belts

How easy is installation and what should I prepare?

Installation is straightforward when the replacement alternator matches the original 11SI layout. Prepare basic hand tools, verify belt alignment and torque specs, and disconnect the battery before working to prevent short circuits.

• Direct‑fit design—no bracket modifications when matched correctly
• Simple bolt‑on replacement using existing mounting holes
• Reattach battery cable to M8 B+ stud and connect labeled spade wires
• Verify belt tension and electrical connections before starting engine

Who is this for: Technicians, marine mechanics and boat owners seeking a cost-effective direct replacement for worn or failed 11SI alternators. This DB Electrical 400-12300 alternator suits vessels that require a 12V 95A output, a clockwise rotation, a 6‑groove 63mm pulley, and the common 11SI mounting and terminal layout. Always compare the unit’s mounting holes, pulley size and terminal types to your original alternator to ensure a proper fit before purchase.

Replaces OEM numbers including Indmar 575014, Delco 8400013/8600002, Arco Marine 20827, Arrowhead ADR0424/400-12300, EMP 4-6451, J&N 400-12213/400-12300, Lester 8723 and Sierra 18-6451.