Blue Sea Systems
Blue Sea e-Series Selector 9002e wiring diagram
Blue Sea 9002e selector with alternator field disconnect: OFF / 1 / 2 / 1+2. Rated 350 A continuous, 600 A for 5 minutes and 1200 A for 30 seconds in its installation sheet. F1/F2 field-control contacts are separate from the three main studs.
Wiring diagram
How the BS e-Series is wired.
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Cable sizing for this example
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Installation notes
Before you install.
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Verified against the manufacturer's documentation, checked 2026-10-01. Manufacturer documentation →
Which selector does this entry represent?
The catalog model is Blue Sea 9002e, the e-Series selector with alternator field disconnect (AFD). Its older internal identifier contains 9001e; that does not make the two switches interchangeable. The 9002e has three main studs and two smaller field contacts. Confirm the number on the actual switch before using these instructions.
The 9002e installation sheet, PDF pages 1–2, supplies the ratings and rear-terminal drawing. No printed revision identifier was found on this two-page sheet.
Where do the main cables land?
The drawing's 1 and 2 represent the two battery-bank positive connections. C represents the switch's common output to the starter or distribution circuit. Battery negatives remain on their separate common return system; they do not connect to these studs.
Position 1 selects bank 1, position 2 selects bank 2, and 1+2 parallels both banks at the common output. Combining banks also allows current between them. Check that the banks and their charging arrangements permit that connection before using 1+2. The switch does not regulate charging or provide overcurrent protection.
What do the AFD contacts do?
The manufacturer's rear drawing marks F1 and F2 separately from the high-current studs. Its instructions place these contacts in the field wire between a compatible alternator and external regulator. They do not carry the alternator's charging output. Confirm the regulator's approved field-disconnect arrangement before connecting them.
The catalog drawing omits F1/F2. A three-cable drawing therefore does not demonstrate working alternator protection. Despite the AFD feature, Blue Sea explicitly instructs users to turn appliances off before OFF and not to select OFF while the engine runs.
Which installation limits matter?
The downloaded sheet lists 350 A continuous, 600 A for five minutes, and 1200 A cranking for 30 seconds. These are separate duties. It specifies one 4/0 AWG cable per terminal to achieve its ratings and warns that smaller cables reduce the rating.
The main studs are 3/8-inch–16; the specified torque is 140 in-lb (15.82 N·m). Follow the sheet's terminal stack and mounting cutout, keep the switch accessible near the batteries, and provide the circuit's required fuses independently. Cable length, routing, battery fault current and alternator-control wiring remain installation decisions outside this terminal map.
Fit check
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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
Blue Sea 9002e selector with alternator field disconnect: OFF / 1 / 2 / 1+2. Rated 350 A continuous, 600 A for 5 minutes and 1200 A for 30 seconds in its installation sheet. F1/F2 field-control contacts are separate from the three main studs.
Connection limits are listed in the terminal map. Use the manufacturer's documentation for the full specifications.
Terminal map
Catalog connection points, current direction and planning limits. Check the manufacturer's pinout and connector ratings before installation.
1
neutral · input
2
neutral · input
C
neutral · output
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. Wire sizes and fuse ratings apply to the connected example, not a fixed cable size for this component. Set your actual equipment, current, lengths and installation conditions in Crimp before choosing hardware.
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