1.7 Wire Routing & Physical Layout¶
Wire Protection Standards¶
All wire runs require appropriate protection based on location and environment:
Protection Methods¶
| Method | Application | Products |
|---|---|---|
| Braided Sleeve (expandable) | Preferred wrap for power runs and cabin/trunk bundles | PET expandable braid sized to bundle OD; plain or with a tracer stripe for harness ID — see Protective Sleeve & Tracers |
| Split Loom | General protection, bundling multiple wires; short/branchy small-wire runs | 1/4" to 1" diameter, slit for easy installation |
| Heat Sleeve | Engine bay, exhaust proximity | Fiberglass sleeve rated 500°F+, 1/2" to 1" |
| Abrasion Sleeve | Frame rail contact, sharp edges | Braided nylon or polyester |
| P-Clamps | Securing runs to frame/body | Rubber-lined, stainless steel |
| Grommets | Firewall/body penetrations | Rubber with appropriate ID for wire bundle |
| Heat Shrink | Terminal connections, splice protection | Adhesive-lined marine grade |
| Spiral Wrap | Areas needing frequent access | Allows wire additions without re-routing |
Protection by Location¶
| Location | Primary Protection | Secondary Protection | Notes |
|---|---|---|---|
| Engine Bay | Heat sleeve | Split loom | Within 12" of exhaust use heat sleeve |
| Frame Rails | Split loom | P-clamps every 18" | Abrasion sleeve at metal contact points |
| Wheel Wells | Split loom | Abrasion sleeve | Water exposure - seal all connections |
| Under Vehicle | Split loom | P-clamps every 12" | Maximum protection from road debris |
| Firewall | Grommets | Heat shrink at penetration | Seal grommets with RTV silicone |
| Interior | Split loom or spiral wrap | Minimal | Behind panels, minimal exposure |
High-Current Cable Protection¶
| Circuit | Wire Gauge | Protection Required |
|---|---|---|
| Alternator → START battery | 2/0 AWG | Heat sleeve (engine bay) → split loom (frame) |
| PMU power feed | 2/0 AWG | Heat sleeve entire run (engine bay exposure) |
| START+ forward-bus feed | 2 AWG | Heat sleeve (engine bay) → braided sleeve (cabin run, H2) |
| BCDC inter-battery | 4 AWG | Split loom + P-clamps (under vehicle) |
| Winch cables | 1/0 AWG | Split loom + abrasion sleeve (frame contact) |
| Battery grounds | 2/0 AWG | Heat sleeve (engine) → split loom (frame) |
🔧 Driver Rear Wheel Well (START Battery)¶
High-current power distribution from START battery:
| Circuit | Wire Gauge | Distance | Destination | Current | Notes |
|---|---|---|---|---|---|
| Alternator charging input | 2/0 AWG | 8 ft | FROM Alternator (engine bay) | 270A | Charges START battery - see Alternator |
| Starter motor power | 2/0 AWG | 6 ft | TO Starter motor (engine bay) | 400-600A | Brief cranking load - see Starter |
| PMU24 power feed | 2/0 AWG | 7 ft | TO PMU24 (engine bay) | 220A max | Via 250A CB - see PMU |
| START+ Forward Dist Bus feed | 2 AWG | ~8 ft | TO engine-bay busbar (fan/iBooster/TCU) | ~108A peak | Via 150A master CB - see START+ Forward Distribution Bus |
| BCDC input feed | 4 AWG | 5-6 ft | TO BCDC (passenger rear wheel well) | 50-55A | Via 80A CB - see BCDC |
| Primary ground | 2/0 AWG | 3 ft | TO Rear frame rail | 600A+ peak | Primary return path |
| Battery cross-ground | 1/0 AWG | 5-6 ft | TO AUX battery- (passenger) | BCDC reference | Critical for BCDC operation |
Routing: Driver rear wheel well → up inside driver rear quarter sill → forward along inside floor board / side wall (driver side) → driver A-pillar area → driver-side firewall grommet → engine bay. Path is fully inside the body (no exposed frame rail). The PMU feed and the START+ Forward Dist Bus master feed (2 AWG) share this driver-side path as part of harness H2. BCDC input (4 AWG) takes the H3 cross-cab path instead (under rear bench seat to passenger side).
🔋 Passenger Rear Wheel Well (AUX Battery)¶
Power distribution from AUX battery:
| Circuit | Wire Gauge | Distance | Destination | Current | Notes |
|---|---|---|---|---|---|
| Warn ZEON 10-S Winch power | 1/0 AWG | 13 ft | TO Front bumper winch | 250A typ, 409A peak | Direct connection (no CB) - see Recovery Systems |
| Warn ZEON 10-S Winch ground | 1/0 AWG | 13 ft | TO Winch motor ground | 250A typ, 409A peak | Return path - routing ⚠️ TBD #106 |
| Forward feed (Firewall CONSTANT bus) | 2/0 AWG | ~13 ft | TO Firewall CONSTANT Bus (cabin trunk) | ~154A max | Protected by 300A CB at battery - feeds SwitchPros + BODY PDU (Fusion head unit rides the BODY PDU via CB30) |
| SafetyHub local feed | 2 AWG | ~2 ft | TO SafetyHub 150 (local in wheel well) | ~100A max | Protected by 150A CB at battery |
| BCDC output | 4 AWG | Short | FROM BCDC (local in wheel well) | 50A | Charging input to AUX battery |
| Primary ground | 2/0 AWG | 3 ft | TO Rear frame rail | ⚠️ TBD #124 | Chassis-grounded accessory return only — winch returns via dedicated 1/0 H1 cable to AUX battery−, not chassis |
| Cross-ground reference | 1/0 AWG | 5-6 ft | FROM START battery- (driver) | BCDC reference | Critical for BCDC operation |
Routing:
- Forward feed (2/0 AWG) + Winch power/ground (2× 1/0 AWG) (H1): Passenger rear wheel well → up inside passenger rear quarter sill → forward along inside floor board / side wall (passenger side) → A-pillar area → through a single sealed 2-piece grommet at the passenger firewall (continuous cables, no firewall break) → forward feed terminates at Firewall CONSTANT bus; winch cables continue to engine bay → grille → front bumper. Three heavy cables bundled together. Fully inside body, no exposed frame rail.
- BCDC input + cross-ground reference (H3): Under the rear bench seat cushion → passenger rear wheel well. Short, dry, physically protected.
- SafetyHub local feed (2 AWG): ~2 ft local in wheel well, no routing concern.
⚙️ Engine Bay¶
Engine compartment wiring:
| Circuit | Wire Gauge | Distance | Source | Destination | Current | Notes |
|---|---|---|---|---|---|---|
| Alternator to battery | 2/0 AWG | 8 ft | Alternator | START battery+ | 270A | See Driver Rear Wheel Well section |
| Starter motor | 2/0 AWG | 6 ft | START battery+ | Starter motor | 400-600A | See Driver Rear Wheel Well section |
| START+ Fwd Bus feed | 2 AWG | ~8 ft | START battery+ (150A CB) | Engine-bay busbar | ~108A peak | Rear-to-front master feed (H2) - see START+ Forward Distribution Bus |
| Busbar → Radiator fan | 4 AWG | short | Engine-bay busbar | Radiator fan | 53A | Via 60A CB (local engine-bay feed) |
| Busbar → iBooster main | 8 AWG | short | Engine-bay busbar | iBooster | 40A peak | Via 50A CB (local engine-bay feed) |
| Busbar → TCU | 12 AWG | short | Engine-bay busbar | Turbolamik TCU (trans) | 15A | Via 25A CB; TCU leg is harness H9 |
| Engine block ground | 2/0 AWG | 8 ft | Engine block | Engine bay ground bus | 600A+ peak | Starter/alternator return |
| Frame ground | 2/0 AWG | 3 ft | Engine bay ground bus | Front frame rail | 600A+ peak | Chassis ground point |
BCDC Location: Passenger rear wheel well (near AUX battery) - charges AUX battery from START battery/alternator
🏠 Firewall Cluster (Cabin Side, Passenger Area)¶
Cabin distribution cluster mounted on the firewall - co-located components fed by the 2/0 AWG forward feed from AUX battery:
| Component | Wire Gauge | Distance | Source/Destination | Notes |
|---|---|---|---|---|
| Firewall CONSTANT Bus (input) | 2/0 AWG | ~13 ft | FROM AUX battery+ via 300A master CB | Heavy feed via H1: passenger floor/side wall → A-pillar → firewall (resolved 2026-05-30) |
| Bus → SwitchPros | 2 AWG | ~2 ft | TO SwitchPros power module | Via 150A CB |
| Bus → BODY PDU | 2 AWG | ~2 ft | TO BODY PDU | Via 100A CB |
| AUX bat → JL Audio MV800/8i Amp | 4 AWG | ~3-4 ft | TO MV800/8i amp (under rear seat) | Via 100A CB at AUX battery (not via firewall bus) |
| SwitchPros Ground Bus | 1/0 AWG | ~3 ft | TO chassis ground at firewall | Lighting/aux load returns |
| SwitchPros control cable | Multi-pin | ~5 ft | TO SwitchPros panel on dash | Standard SwitchPros cable |
| SwitchPros outputs (12 circuits) | Various | ⚠️ TBD #107 | TO various loads (front/cabin/rear/roof) | Mostly short forward fan-out from firewall |
🚪 Firewall Penetrations¶
Wire bundles passing through firewall:
| Penetration | Location | Direction | Circuits | Wire Count | Notes |
|---|---|---|---|---|---|
| Cummins Harness | Factory location | Engine ↔ Cabin | Engine harness, J1939 CAN | Factory | Dedicated bulkhead connector |
| Deutsch HDP24-24-29 | ⚠️ TBD #61 (near PMU) | Bidirectional | All custom wiring | 17 | Single weatherproof connector |
| Temp Probe Grommet | Near grille | Cabin → Grille | BIM-17-2 temp sensor | 2 (22 AWG) | Small grommet, twisted pair |
J1939 CAN Bus
J1939 CAN High/Low wires tap into Cummins harness at firewall punch-through, then route to Dakota Digital 01-2-J1939 module on firewall HDPE panel (cabin side).
Complete Details: See Firewall Ingress for Deutsch HDP24-24-29 connector pinout and BOM
🏠 Cabin & Dashboard¶
Interior wiring and controls:
| Routing Path | Circuits | Method | Notes |
|---|---|---|---|
| Dash → Console | Switch panels, USB, radio | ⚠️ TBD #62 | Under dash routing |
| Firewall → Dash | Dakota Digital cluster, CT4, controls | Behind dash | Main instrument panel area |
Dakota Digital Firewall Panel (Cabin Side):
| Component | Function | External Connections |
|---|---|---|
| 01-2-J1939 | J1939 CAN interface | CAN High/Low from Cummins harness (engine side) |
| GPS-50-2 | GPS speed sensor | Antenna (dash/windshield mount) |
| BIM-22-3 | TPMS module | Wireless (no external wiring) |
| BIM-17-2 | Compass/outside temp | Temp probe (through firewall to grille) |
| Main harness | BIM/IO cable | Dakota Digital cluster in dash |
Panel Location: ⚠️ TBD #39 - firewall behind dashboard Mounting: ⚠️ TBD #39 - HDPE sheet dimensions and fasteners
📦 Cargo & Rear¶
Rear area wiring:
| Routing Path | Circuits | Method | Notes |
|---|---|---|---|
| Cab → Cargo | Rear lights, compressor, lockers | ⚠️ TBD #63 | Under seats or floor channels |
| Passenger rear wheel well → Cargo | SwitchPros rear outputs | ⚠️ TBD #63 | Rear auxiliary power (avoid exposed frame rail) |
🌐 Roof & Exterior¶
External and overhead wiring:
| Routing Path | Circuits | Method | Notes |
|---|---|---|---|
| Roof/Roll bar | Light bars, dome lights | ⚠️ TBD #64 | A-pillar or along roll bar |
| Front exterior | Turn signals, offroad lights | Engine bay to front | SwitchPros outputs |
| Rear exterior | Tail/brake/reverse, license plate | Cargo to rear | PMU and SwitchPros outputs |
Ground Points Summary¶
Primary grounding locations - see Section 1.5 - Grounding Architecture for complete details:
| Location | Ground Bus | Wire Gauge | Connections | Notes |
|---|---|---|---|---|
| 🔧 Driver rear wheel well | Engine bay ground bus | 2/0 AWG | START battery-, engine block, frame rail, AUX battery | Primary ground hub |
| 🔋 Passenger rear wheel well | Rear frame rail | 2/0 AWG | AUX battery- | AUX battery ground point |
| 🏠 Firewall (cabin side) | Firewall stud bus | 4 AWG max | Body electronics, sensors | Cabin electronics ground |
| ⚙️ Firewall (engine side) | Engine bay ground bus | Various | PMU, controllers, accessories | Engine bay ground hub |
| 🌐 SwitchPros controller | SwitchPros ground bus | 1/0 AWG | Lighting/aux loads | Dedicated lighting ground |
Related Documentation¶
- Harness Inventory - Fabricatable harness overview (H1–H9): summary, harness map, bundle interference assessment, and optimization notes
- Power Distribution - H1, H2, H3 with tub-map diagram
- Lighting & SwitchPros - H4, H5 with tub-map diagram
- Controls, Recovery & Drivetrain - H6–H9 with tub-map diagram
- Grounding Architecture - Complete grounding system design
- START battery Distribution - Driver rear wheel well power
- AUX battery Distribution - Passenger rear wheel well power
- PMU - Power management unit
- SafetyHub - Fused distribution
- BCDC - DC-DC charger
- Alternator - Charging system routing
- Starter - Starter motor routing
- Firewall Ingress - Detailed firewall penetrations and grommet specifications
- Recovery Systems - Winch installation and wiring