Blue Sea Systems, 3003, HD-Series Heavy Duty Selector Battery Switch with AFD
Manufacturer Info
Switches isolated battery banks to all loads or combines battery banks to all loads
- Includes AFD (Alternator Field Disconnect)
- Make-before-break contact design allows switching between battery banks without power interruption
- Ignition protected - safe for installation aboard gasoline powered boats
- Case design allows surface or rear panel mounting
- Accepts two 4/0 AWG (95mm2) battery cables
- Instructions
- Mounting Diagram
Specifications | |
---|---|
Switch Type | Selector 4 Position |
Color | Grey |
Switch Positions | 4 |
Battery Combine | Yes |
Alternator Field Disconnect | Yes |
Maximum Voltage | 32V DC |
Terminal Stud Torque | 220 in-lb (24.86 Nm) |
Continuous Rating | 500A |
Intermittent Rating | 700A (5 min) |
Cranking Rating 30 sec | 1600A |
Battery Inputs | 2 |
Cable Clearance For 4/0 AWG Cables | 1.10in (27.94 mm) |
Cable Quantity to Meet Ratings | Two Cables / Terminal |
Cable Size to Meet Ratings | 4/0 AWG (120mm2) |
Mounting Holes | Accept 1/4" (M6) Screw |
Terminal Stud Size | 1/2" (M12) |
Weight | 1.25lb (0.57 kg) |
Product Reviews
We're currently collecting product reviews for this item. In the meantime, here are some reviews from our past customers sharing their overall shopping experience.
4.8
Out of 5.0

Overall Rating
96%
of customers that buyfrom this merchant give
them a 4 or 5-Star rating.
March 31, 2025 by Lee H. (United States)
“Fantastic Company”
March 28, 2025 by Winston C. (Cayman Islands)
“Enjoyable”
March 27, 2025 by Vadim P. (United States)
“Excellent Company”
March 25, 2025 by JOHN G. (United States)
“thank you”
March 25, 2025 by Douglas G. (United States)
“No shipping options, very expensive!!!”