1.5.4 Firewall Stud Bus¶
Type: Low-Current Ground Distribution Bus Bar
Model: Blue Sea 2105 MaxiBus
Manufacturer: Blue Sea Systems
Product Page: Blue Sea 2105 MaxiBus
Specifications¶
- Capacity: 250A AC/DC continuous, 300V AC / 48V DC max
- Terminals: 12x #10-24 screws, 2x 5/16"-18 studs
- Location: Firewall (cabin side), accessible from dash
- Full Specs: Blue Sea 2105
Stud/Terminal Assignment¶
| Stud/Terminal | Connection | Wire Gauge | Distance | Max Current | Notes |
|---|---|---|---|---|---|
| Stud 1 (5/16") | Chassis Ground (INPUT) | 4 AWG ✓ | ~2 ft | ~50A total | Primary bus ground - to firewall |
| Stud 2 (5/16") | [Available] | - | - | - | Future high-current ground |
| Terminal 1 (#10-24) | Command Touch CT4 | 14 AWG ✓ | ~3 ft | <1A | Steering column controller logic ground |
| Terminal 2 (#10-24) | WS-51C Wiper Controller | 16 AWG ✓ | ~2 ft | ~5A | Dash wiper control - see Wiper System |
| Terminal 3 (#10-24) | BODY PDU | 14 AWG ✓ | ~4 ft | ~3A | Relay coil/logic ground only (high-side switching) |
| Terminal 4 (#10-24) | Dakota Digital Cluster | 16 AWG ✓ | ~2 ft | <1A | Instrument cluster logic ground |
| Terminal 5 (#10-24) | Dakota Digital BIM | 16 AWG ✓ | ~2 ft | <1A | Body interface module |
| Terminal 6 (#10-24) | Fusion MS-RA670 Head Unit | 14 AWG ✓ | ~2 ft | ~5A | Audio head unit - see Audio System |
| Terminal 7 (#10-24) | MLC-RW LED Controller | 16 AWG ✓ | ~2 ft | ~3A | Audio RGB controller - see Audio System |
| Terminal 8 (#10-24) | WolfBox Camera/Mirror | 16 AWG ✓ | ~2 ft | ~5A | Rearview mirror/camera system |
| Terminal 9 (#10-24) | [Available] | - | - | - | Future dash electronics |
| Terminals 10-12 (#10-24) | [Available] | - | - | - | Future expansion (3 terminals) |
Utilization: 9 of 14 used (1 stud + 8 terminals used, 1 stud + 4 terminals available)
Purpose: Clean ground reference for cabin electronics - keep separate from high-current grounds to minimize noise
Installation¶
Mounting: Firewall (cabin side), close to dash electronics
Ground Path: Bus → chassis ground (4 AWG, handles ~50A total load) → START battery negative bus (via 2/0 AWG main chassis ground)
Critical: Clean metal-to-metal connection to firewall/chassis, protected from water/moisture