The INEOS Grenadier Station Wagon's rooftop DTP outlets run on two 25A circuits: EXT2 supplies one outlet, while EXT3 supplies three outlets on a shared circuit. Cable selection comes down to four decisions:
- Connector type: DTP-to-Weather Pack for most accessories, DTP-to-2.1mm for Starlink Mini, DTP splitter if you're running two devices from one port
- AWG gauge: 16 AWG for anything under 10A (Starlink draws 5A, LED lights draw 5–8A); 14 AWG for compressor fridges and accessories drawing 10–15A
- Exterior protection: use a sealed connector assembly and automotive wire whose jacket is rated for the expected UV, temperature, abrasion, and chemical exposure
- EXT2 vs EXT3: EXT2 is a dedicated 25A port; EXT3 controls three ports together. Add inline switches to control accessories individually
1. The Grenadier's Power Architecture (What the Ports Actually Give You)
The Grenadier's auxiliary power option routes factory-wired circuits to specific locations around the vehicle. Most roof-mounted builds connect through the rooftop DTP ports.
The overhead switch panel (standard on vehicles with the High Load Auxiliary Switch Panel option) gives you seven circuits:
| Switch | Location | Connector Type | Rating |
|---|---|---|---|
| EXT1 | Engine bay | Bare wire | 10A fused |
| EXT2 | Roof — right front (single port) | DTP (dedicated) | 25A fused |
| EXT3 | Roof — left front, left rear, right rear | DTP (3 ports, shared circuit) | 25A fused (shared) |
| EXT4 | Front winch / rear of vehicle | Front winch provision / rear NATO outlet | 500A front provision; 350A rear NATO outlet |
| EXT5 | Engine bay | Bare wire | 25A fused |
| INT1 | Driver footwell | Bare wire | 10A fused |
| INT2 | Passenger footwell | Bare wire | 10A fused |
Only the four rooftop outlets use Deutsch DTP connectors. The footwell and engine-bay circuits terminate in bare wires. This distinction prevents owners from ordering DTP adapters for under-hood or cabin connections.
EXT3 controls three roof DTP ports on a single shared 25A circuit. All three activate together when EXT3 is toggled. If you're running a Starlink Mini on one port and an LED light bar on another, both are live or both are off. Inline switches provide individual control. Most owners who want per-device control add a relay-based solution downstream of the DTP port.
As one forum member explained when documenting the Grenadier's DTP specifications:
"The 25 amp Deutsch plugs used in the INEOS are two pin DTP style plugs, with size 12 pins rated at 25 amps (14–12 AWG wire size). These plugs can be found on the roof (4 locations on the IG, but only 2 locations on the QM) — if you selected the auxiliary power option. There are no Deutsche DTP plugs in the footwells, battery compartment or under the bonnet, only bare wires."
— TheIneosForum.com — Deutsch DTP plugs technical thread
For full switch mapping, amperage logic, and voltage-drop calculations, see DVA's DTP Connector System & Accessory Wiring Architecture guide.
Port Locations: Where Each Circuit Terminates
The locations below are shown on a left-hand-drive Station Wagon. INEOS identifies EXT2 as the front-right roof outlet and EXT3 as the front-left, rear-left, and rear-right roof outlets. The Quartermaster uses two roof outlets rather than four. Roof outlets require the High Load Auxiliary Switch Panel & Electrical Preparation option.
Thank you to Jean Mercier and The INEOS Forum contributors for documenting access to the footwell auxiliary wires: INT1 driver-side footwell thread and INT2 passenger-side footwell thread. Jean's INT2 testing found power with both PWR and INT2 switched on; treat community procedures as owner-documented experience and verify wiring on your vehicle before connecting a load.
2. AWG Gauge: Match the Wire to the Draw
Wire gauge determines how much current a cable can carry safely. Wire that is too thin for a high-current device generates heat and can start a harness fire. Oversized wire adds cost and bulk. Match AWG to the device's maximum current draw while staying within the circuit limit.
Understanding the draw math
Current draw (amps) = Power (watts) ÷ Voltage (volts). The Grenadier runs 12V nominal (13.8–14.4V when the engine is running). For sizing, use 12V to be conservative:
| Accessory | Typical Draw | At 12V | Recommended AWG |
|---|---|---|---|
| Starlink Mini | 60W input rating (manufacturer specification) | ~5A | 16 AWG |
| LED flood lights (2 × 40W) | ~80W | ~7A | 16 AWG |
| Compressor fridge (12V portable) | 120–180W peak | 10–15A | 14 AWG |
| Air compressor (small) | 200–300W | 17–25A | 12 AWG |
Most rooftop accessories, including Starlink, LED lighting, action cameras, and dash cameras, can use 16 AWG wire within the listed current and length limits. Compressor fridges warrant 14 AWG. An air compressor running from a rooftop DTP port pushes against the 25A circuit limit and should use 12 AWG if the run is more than 6 feet.
Voltage drop on long cable runs
Wire resistance increases with cable length. A standard 16 AWG copper conductor runs 4.02 mΩ per foot. For a 10-foot run at 5A:
- Voltage drop = 5A × (10 ft × 2 × 4.02 mΩ/ft) = ~0.4V
- At 12V, that is a 3.3% drop, which is within tolerance for most accessories
- At 15A through 16 AWG over 10 feet: ~1.2V drop, or a 10% loss
If your cable run from the DTP port to the accessory exceeds 6 feet at high current draws, step up to 14 AWG. One forum member running Starlink Mini from a DTP port noted that for long interior-to-roof cable runs, a 12V-to-24V (or higher) converter on the line reduces amperage and allows thinner wire for the long segment.
"Needs about 60W max, so about 5 amps. Could use the existing DTPs... If you're making a longer run on power, definitely consider tossing a 12V→24V (or 36V or 48V) converter in the mix to drop amperage on the small wiring running to the dish."
— TheIneosForum.com — Starlink Mini thread, pg. 2
3. Six DTP Cable Types (and When to Use Each)
The mating cable end used at the Grenadier rooftop outlet is a DTP06-2S housing with socket contacts. Confirm the cavity pinout and polarity before energizing any custom-built cable. The other end depends entirely on what you're powering. There are six common cable configurations:
DTP → Bare Wire
For custom builds that terminate in bare wire. Use the specified crimping tool, confirm polarity, and verify the finished cable with a multimeter before connection.
DTP → Weather Pack
For accessories already fitted with a 2-port Weather Pack connector, including compatible light bars, LED pods, and auxiliary equipment. The adapter connects the accessory without cutting its harness.
DTP → 2.1mm Barrel
Connects a rooftop DTP outlet to Starlink Mini. The Mini uses a 2.1mm DC input. 16 AWG, 1m–3m lengths. Handles 12V–48V input range of the dish. No adapter chain required.
DTP Splitter
One port, two accessories. Splits one DTP power connection into two outputs. Useful for EXT2 (the single dedicated port) when you want to run two devices without occupying another EXT3 port. Respect the combined 25A circuit limit.
DTP Extension Cable
Adds cable length without splicing. Male DTP on one end, female DTP on the other. Useful when your accessory's cable reaches the port but you need a few more feet for routing flexibility.
IP65 Pre-Made Harness
Pre-assembled 16 AWG harnesses with an IP65-rated connector assembly and inline fuse. They eliminate onsite crimping and connector sourcing.
4. Exterior Cable Protection: Use a Sealed, UV-Resistant Assembly
For permanent rooftop wiring, evaluate the complete assembly: mated connectors, contact seals, cable jacket, splices, strain relief, and the accessory inlet. An IP rating applies only to the assembly that was tested; it does not automatically apply to every wire or adapter attached to a sealed DTP connector.
Use automotive wire with a jacket rated by its manufacturer for the expected temperature, abrasion, chemical, and UV exposure. Keep splices sealed and supported, route the cable away from sharp edges and heat, and replace protective caps whenever a rooftop outlet is unused. INEOS also instructs owners to keep auxiliary-outlet connections free of dirt, debris, and moisture.
5. Running Multiple Accessories from DTP Ports
As builds get more capable, owners increasingly want to run several accessories off the roof DTP ports simultaneously: a Starlink Mini, a front LED light bar, and one or two side flood lights. The factory system supports this, but with one important constraint: the EXT3 circuit is shared across three ports.
Forum member Andy described exactly this situation when planning his multi-accessory build:
"I have work lights on the left and right sides, together with the factory LED front lightbar. I wanted to install a Starlink Mini and a rear work light and be able to switch each of these on and off individually. [Using the roof DTP port with a standard cable] allows me to power the Starlink; however, all accessories need to be on as they are all switched on the overhead panel."
— TheIneosForum.com — Inline DTP Switch thread
There are three ways owners address this:
- Relay-based distribution block: Wire a distribution block with individual relay switches between the DTP port and each accessory. Each relay gets a discrete control trigger. Cleanest approach for permanent multi-accessory builds.
- DTP splitter + inline switches: Use a DTP splitter to create two outputs from one port, then add an inline switch on each leg. Simpler to install but adds more hardware in-line.
- Use EXT2 for always-on accessories: Put your Starlink or battery charger on EXT2 (the dedicated single port that's switched independently) and run your lights from EXT3. This gives you basic two-group control without any additional switching hardware.
Current budget when running multiple accessories
EXT3's 25A is shared. If you're running three accessories from three EXT3 ports simultaneously, their combined draw must stay under 25A:
- Starlink Mini: ~5A
- 50W LED roof bar: ~4A
- 2 × 40W LED flood lights: ~7A
- Combined: ~16A — well within 25A limit
Running a compressor fridge (10–15A) alongside an LED array on the same EXT3 circuit would draw 17–22A. That stays below the 25A limit, but compressor startup current can open the circuit protection. Power the fridge from a dedicated circuit, route a longer feed from an INT circuit where its rating is sufficient, or use EXT2.
6. Every DVA DTP Cable and What It Does
DVA's current Grenadier cable range covers direct device power, connector conversion, circuit splitting, and longer sealed runs. Match the vehicle-side connector, accessory-side connector, cable length, and combined current before ordering. A splitter creates more connection points; it does not increase the EXT circuit's 25A limit.
| DVA Cable | Primary Purpose | Use It When |
|---|---|---|
| Starlink Mini DTP Power Cable | DTP06-2S to 2.1mm DC; 16 AWG; 1m, 2m, or 3m | Powering Starlink Mini directly from an EXT2 or EXT3 rooftop outlet. |
| DTP06-2S to 2-Way DTP04-2P Splitter | Turns one vehicle outlet into two equal DTP04-2P outputs | Two DTP-equipped accessories are close together and their combined draw stays within the source circuit limit. |
| DTP06-2S to Unbalanced 2-Way DTP04-2P Splitter | Two DTP outputs with 15cm and 100cm legs | One accessory sits near the outlet and a second needs a longer branch, such as front- and rear-door lighting from one source. |
| DTP06-2S to IP65 Waterproof Connector Cable | Adapts the factory DTP outlet to a sealed 2-pin accessory connection | Connecting light bars, work lights, antennas, or devices with smaller AWG16–AWG24 pigtails without crimping them directly into DTP contacts. |
| DTP06-2S to IP65 Waterproof Splitter | One DTP input to two sealed IP65 outputs | Running two low-current accessories with IP65 connectors from one rooftop outlet. |
| DTP06-2S to 2-Port Weather Pack Cable | 18-inch DTP-to-Weather Pack adapter | The accessory already has a compatible female 2-pin Weather Pack connector. |
| DTP06-2S to Anderson SB50 | 3-meter, 12 AWG quick-disconnect adapter; PDP recommends up to 15A | Portable equipment, field-service loads, or distribution hardware uses an Anderson SB50 connection. |
| DTP04-2P Female to IP65 Waterproof Cable | 3-meter, 16 AWG sealed extension from a DTP04-2P male source | Routing from a compatible splitter or harness toward front-bumper lighting or another distant IP65-connected load. |
PowerVault™ Utility Hub R2: Portable Power Without Building a Harness
The PowerVault™ Utility Hub R2 plugs into a Grenadier EXT2 or EXT3 outlet through its included 1-meter DTP-to-Anderson cable. Four magnets hold the hub to a steel body panel, door, or swing-out. Outputs include two USB-C ports rated up to 65W each, two USB-A ports rated up to 22.5W each, one 12V socket, and a switch-controlled flashlight. It is designed for rain, mud, and dust exposure but must not be submerged. Total output remains limited by the connected vehicle circuit.
Best for: a movable camp-power point for phones, laptops, cameras, lighting, and 12V accessories without drilling the body or installing a permanent distribution panel. Switch the hub off when parked and not in use.
View all DTP cables · View Power & Connectivity
7. Five Cable Installation Mistakes Grenadier Owners Make
Most cable failures start with a small installation detail rather than the accessory itself. Check these five points before energizing a new circuit.
Wrong polarity on DIY DTP builds
DTP housings are mechanically keyed, but a custom cable can still be assembled with positive and negative contacts in the wrong cavities. Verify the documented cavity pinout and polarity with a multimeter before connecting an accessory.
Using open-barrel pins instead of closed-barrel
Use closed-barrel DTP pins and sockets. Forum builders report that their crimps resist vibration better than open-barrel contacts.
Routing cable without strain relief
A cable hanging from a DTP port on a vibrating roof concentrates stress at the connector housing. Provide strain relief close enough to the connector that cable movement cannot load the housing or contacts under vibration.
Leaving the DTP port open when not in use
The Grenadier's DTP ports come with white sealing plugs. Remove them for connections, but always reinsert them when a port is unoccupied. Exposed DTP contacts on a muddy trail accumulate contamination that can cause arcing on future connections.
Exceeding 25A on EXT3 with multiple accessories
EXT3 controls three ports on one fused circuit. Running a compressor, a light bar, and a Starlink from three EXT3 ports simultaneously may push the circuit past its fused rating. Plan your current budget before building. The circuit protection prevents an overload, but calculating the combined draw avoids losing power on the trail.
Use the sealing-plug test to verify your connection
When inserting a DTP connector, you should feel and hear the wedgelock click into position. If it wiggles, the wedgelock isn't seated. A loose connection will eventually lose contact under vibration. The worst time to discover this is mid-trail, 40 miles from cell service.
Bonus: Direct Battery Power for High-Draw and Complex Builds
Battery and under-hood connection points: the Grenadier's 12V vehicle battery is under the left rear passenger seat. The engine bay provides separate connection points for specific electrical functions. INEOS provides a covered positive terminal and a chassis grounding point under the hood for jump-starting. The owner's handbook identifies those points for jump-starting; it does not approve the positive jump terminal as a permanent accessory feed. For an under-hood accessory, use the factory EXT1 10A or EXT5 25A preparation when the load fits. If the accessory needs more current, have a qualified installer or INEOS dealer confirm the connection point and route a dedicated fused feed from the battery area.
How Much Current Can a Direct Feed Carry?
A direct battery cable has no universal current rating. The safe limit is the lowest rating in the complete path: battery connection, fuse or breaker, cable gauge and length, relay or contactor, distribution block, connectors, grounds, and the accessory itself. Size the cable from the accessory manufacturer's maximum continuous current and startup or inrush specification. Average draw is not a safe sizing value.
| Example Load | Approx. Current at 12V | Energy Used per 24 Hours |
|---|---|---|
| Small control module | 0.05A (50mA) | 1.2Ah per 24 hours |
| 1A accessory | 1A | 24Ah per 24 hours |
| Starlink Mini at its 60W input rating | 5A | 120Ah per 24 hours |
| 10A combined load | 10A | 240Ah per 24 hours |
These are arithmetic examples: amp-hours = amps × hours. INEOS specifies a 12V 105Ah EFB H9 battery and an Intelligent Battery Sensor that monitors voltage, current, and temperature. The 105Ah label is nominal capacity, not a safe accessory budget; using a starting battery deeply can leave insufficient reserve to crank the engine. For parked loads, use a low-voltage disconnect or a separate auxiliary battery system designed for deep cycling.
When a Separate Relay or Contactor Makes Sense
Use a properly rated relay or contactor when a dashboard switch, ignition trigger, timer, or control module should command a load that exceeds the controller's output rating. The control wire energizes the relay; the fused battery cable carries the accessory current through the relay contacts. This keeps high current out of small switches and long control-wire runs.
- Simple single load: battery → source fuse → relay → accessory, with the relay triggered by an approved switched source.
- Complex installation: battery → source fuse → main contactor or low-voltage disconnect → fused distribution block → individual branch circuits.
- Motor or compressor: select contacts for the manufacturer's startup/inrush current and verify the relay is rated for the load type and duty cycle.
- Parked operation: use an ignition-controlled relay, timer, or low-voltage disconnect so loads cannot remain energized indefinitely.
A conventional relay coil also consumes power while held on, and control modules can have standby draw. Include every always-on controller in the parked-current calculation. Measure the completed system after the vehicle has entered sleep mode; do not rely only on catalog estimates.
Fuse at the Source
Every new positive conductor connected directly to a battery or charging source needs overcurrent protection close to that source. Blue Sea Systems' summary of ABYC E-11 specifies protection within 7 inches (175mm) of the connection unless an allowed exception applies. The fuse protects the cable, so its rating must not exceed the safe ampacity of the smallest conductor or component downstream.
The under-hood positive post is documented by INEOS as a jump-start terminal. A permanent high-draw installation should use a connection point approved for that purpose, include source-side circuit protection, preserve the Intelligent Battery Sensor's monitoring path, and be reviewed by a qualified installer or INEOS dealer.
Primary references: INEOS Grenadier US/Canada Owner's Handbook (battery location, jump terminals, 105Ah EFB specification, IBS and auxiliary circuits); Blue Sea Systems: DC Circuit Protection; Victron Energy: BatteryProtect.
Related Grenadier Electrical Guides
Power cables are one piece of the Grenadier's electrical ecosystem. These guides cover the system in depth:
- Grenadier DTP Connector System & Accessory Wiring Architecture — full switch mapping, amperage math, and voltage drop calculations
- INEOS Grenadier EXT & INT Auxiliary Power: 7-Circuit Engineering Guide — which circuit handles what, how EXT4 winch circuit works, and interior INT port wiring
- INEOS Grenadier Light Bar & Auxiliary Lighting Guide — which EXT ports to use for each lighting zone, LED specs, and wiring from the DTP system
Sources
- TheIneosForum.com — Deutsch DTP plugs technical thread
- https://cdn.shopify.com/s/files/1/0595/8952/5602/files/EXT-1-EXT-5---744613fb-7109-4153-9eb9-56191cefeba0.jpg?v=1786134079
- https://cdn.shopify.com/s/files/1/0595/8952/5602/files/EXT-3-Passanger-Front---f9da4912-9589-449e-b5fc-6327e6b0e661.jpg?v=1786134079
- https://cdn.shopify.com/s/files/1/0595/8952/5602/files/EXT-3-Driver-Front---5665ae40-05fa-4c4e-843d-cd39b00d11dd.jpg?v=1786134079
- https://cdn.shopify.com/s/files/1/0595/8952/5602/files/EXT-3-Driver-Rear---156014c5-69e9-452c-b376-e3d5e417c096.jpg?v=1786134079
- https://cdn.shopify.com/s/files/1/0595/8952/5602/files/EXT-3-Passanger-Rear---7258aaa8-b426-47b8-8bc5-3d034c9b824d.jpg?v=1786134079
- https://cdn.shopify.com/s/files/1/0595/8952/5602/files/EXT-4---18d0dec1-3f7c-4dc9-b275-3c0089d3749e.jpg?v=1786134080
- https://cdn.shopify.com/s/files/1/0595/8952/5602/files/INT-1---369af756-08c7-4636-aed3-7ade81f041b4.jpg?v=1786134079
- https://cdn.shopify.com/s/files/1/0595/8952/5602/files/INT-2---5dbdf099-3a1a-404a-b6cf-22df24bd2ef7.jpg?v=1786134079
- INT1 driver-side footwell thread
- INT2 passenger-side footwell thread
- TheIneosForum.com — Starlink Mini thread, pg. 2
- TheIneosForum.com — Inline DTP Switch thread
- https://cdn.shopify.com/s/files/1/0595/8952/5602/files/Direct-Battery-Power---bfdbfade-99a4-4036-956b-d423dcf392c6.jpg?v=1786134396
- INEOS Grenadier US/Canada Owner's Handbook
- Blue Sea Systems: DC Circuit Protection
- Victron Energy: BatteryProtect
The DVA Setup for This
Build from verified fitment and documented limits.
Use the live product page and vehicle documentation together. The lowest applicable vehicle, mounting-system, or accessory limit governs.
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