A Garmin SERV or SERV+ display is the part you see, but it is only one piece of the system. Behind it sit wiring harnesses, a CAN network with terminators at each end, adapter cables, and sometimes an EmpirBus switching module. Most of those are sold separately. This guide lists what comes in the box, what you add for a small SERV+ system and for a larger system with a Connect 50, and the mistakes that stop a network from working.
What comes in the box
Garmin lists different box contents for the two versions:
| SERV+ | SERV |
|---|---|
| Display (7" or 10") | Display (7" or 10") |
| 2-pin power cable | 3-pin power cable |
| CAN termination connector | Not listed |
| Trim bezel, mounting hardware and template, documentation | Trim bezel, mounting hardware and template, documentation |
Not included: the wiring harnesses for the SERV+ switching channels, the adapter that connects the display's CAN port to the network, network cables, a fuse, and a microSD card. Garmin's SERV install guide marks the CAN adapter and the power fuse as "not included".
Build 1: a small system on a SERV+ alone
A SERV+ 7" or SERV+ 10" has 6 output channels and 5 configurable inputs of its own. That covers a van or small trailer with a handful of lights, a pump and a fan (see SERV vs SERV+ if you haven't chosen the display). The parts list:
| Part | What it does |
|---|---|
| SERV+ output harness (6-pin) | Connects and controls up to 6 output circuits (Garmin's description) |
| SERV+ input/output harness (8-pin) | Connects the RV-C and LIN data buses and the 5 configurable input channels |
| 4-pin CAN to NMEA 2000 adapter cable | Garmin's SERV install guide shows the CAN port connecting through an adapter (not included); for the SERV+, this adapter takes it from Garmin's 4-pin CAN plug to NMEA 2000 |
| NMEA 2000 backbone/drop cable, 4 m | Runs a device to the backbone, or extends the backbone |
| RV-C multi tap and RV-C interior temperature sensor | Joins RV-C devices at one point; reports cabin temperature to the screen |
Before you order the harnesses, add up your loads. Each SERV+ output handles 1 to 10 A, but the display's total is 30 A, and if two channels run above 8 A the rest must stay at 5 A or less.
Build 2: a larger system with a Connect 50
When you have more circuits than six, a EmpirBus Connect 50 module does the switching, mounted near the loads, and a SERV or SERV+ becomes the control screen (more in adding circuits with a Connect 50). A typical parts list:
| Part | Why |
|---|---|
| SERV 7" / 10" or a SERV+ | Control and monitoring screen |
| A way to connect the display: the 4-pin CAN to NMEA 2000 adapter, or the Mini-Fit / RV-C multi tap route | Garmin's SERV install guide shows both a CAN adapter route and a Mini-Fit route to a multi tap. Which one your build uses depends on the module's network connection, so ask us to confirm before you order |
| EmpirBus Connect 50 v2 (12 V) | The switching module. Garmin's Connect 50 manual allows up to 6 units on one network |
| NMEA 2000 starter kit | The backbone: 6 m backbone cable, 2 m drop cable, 2 m power cable, 2 T-connectors, male and female terminators |
| 4 m backbone/drop cable | A drop from the backbone to the module (if your v2 connects to NMEA 2000; check with us), or a longer backbone |
| EmpirBus multiswitch resistor | For wiring several momentary switches onto one module input |
| NMEA 2000 to RV-C adapter cable (3 m), RV-C multi tap, Mini-Fit to bare wire cable | Connecting to the coach's RV-C side, and landing a connection on a device without a Mini-Fit plug |
For Connect 50 models on NMEA 2000, Garmin's manual says not to plug a T-connector straight into the module. Put a drop cable between the backbone and the unit. That is why the 4 m cable is on the list even with a starter kit. Count T-connectors too: the kit has two, one for the power cable and one for a device. A display and one Connect 50 on the same backbone need a third (Garmin T-connector 010-11078-00, sold separately; ask us).
The network rules that matter
Garmin's NMEA 2000 technical reference sets the rules for the backbone that the starter kit builds:
- Terminators on both ends, and only two. One male and one female terminator go on the sides of the last T-connectors. More than two is not allowed.
- A straight line. T-connectors join side to side. Devices and the power cable plug into the top of a T, never the side, and the backbone never runs through the top of a T.
- Drop length. A drop cable can be up to 6 m (20 ft). Any Garmin cable up to 6 m can be used as a backbone or a drop, so the 4 m cable does either job.
- Power. The backbone connects to 12 V DC through a dedicated NMEA 2000 power cable, switched (ignition or an in-line switch), so it doesn't drain the battery. NMEA 2000 devices run from 9 to 16 V DC.
- Size limits. No more than 100 m (328 ft) between any two points, 78 m (256 ft) of drop cable in total, and 50 devices.
Keep the buses apart. Garmin's SERV install guide warns not to combine the Garmin main CAN bus with the RV-C bus, because it can damage equipment or stop the display working properly. Plan which network each device sits on before you buy adapters. Our RV-C vs NMEA 2000 guide explains the two.
Power and fusing
- SERV+: 10 to 16 V DC supply and a 30 A fuse, per Garmin's specifications. That matches the display's 30 A maximum current, which includes its output loads.
- SERV: 10 to 32 V DC. Garmin's owner's manual and install guide give different fuse sizes, so use the size in the instructions that come with your display.
- Connect 50: Garmin's Connect 50 manual and data sheet put main power on two M6 bolts, with a 50 A maximum for the module.
Garmin's SERV install guide strongly recommends that an experienced installer with the right electrical knowledge does the installation, since wiring the power cable wrongly can damage the vehicle or battery.
Configuration is part of the job
Hardware alone doesn't give you working buttons. The screen layout and switch logic are set up by the installer:
- On the display, installer-only settings turn on the EmpirBus web display (WDU) function and choose the RV Controls pages. Garmin says a complete EmpirBus system needs one or more display products and one or more digital switching modules.
- EmpirBus modules are set up with Garmin's EmpirBus software. The Connect 50 manual refers to EmpirBus Studio. Ask us what the setup involves for your build.
- A finished configuration can be saved from one display to a microSD card and loaded on another compatible display.
Tools for the connectors
The Connect 50 uses two 16-way Molex MX150L connectors. Garmin says to use the correct crimp and extractor tools, plug unused pins to keep the IP65 rating, and use wire up to 2.5 mm². To extend the SERV's Mini-Fit CAN wiring, Garmin calls for 22 AWG wire.
Checklist before you order
- List every circuit with its current draw. Six or fewer, under 30 A in total: a SERV+ on its own may do it. More: plan a Connect 50.
- Decide where each screen and module goes, and measure the backbone run and each drop.
- Note what is already on the coach: an RV-C network, an existing NMEA 2000 backbone, or nothing.
- Count T-connectors: one per device on the backbone, plus one for the power cable.
- Budget for fuses, wire, a microSD card and the setup time.
Send us that list and we will check the parts against it before you order. Everything ships from our warehouse in Upland, California. Browse the full Garmin SERV range. Found it cheaper? We'll beat it.
FAQ
Do I need the NMEA 2000 starter kit if I only buy a SERV+?
Not always. If the display isn't joining a CAN network with other modules, you may need only the harnesses. If it is, and you don't already have a backbone, the starter kit gives you one.
Can I use the starter kit's T-connector to plug in the Connect 50 directly?
For NMEA 2000 Connect 50 models, Garmin's manual recommends against it: use a drop cable between the T-connector and the module. Ask us to confirm how the v2 connects.
Which SERV+ harness do I need?
Usually both. The 6-pin output harness carries the six output circuits; the 8-pin input/output harness carries the inputs and the RV-C and LIN buses.
Can I add more modules later?
Yes. Garmin's Connect 50 manual allows up to 6 units on one network, and the NMEA 2000 rules allow up to 50 devices.