Overview
The NBX-957 is a body-mounted central power distribution box for heavy-truck, bus and large commercial-vehicle platforms — the single enclosure that consolidates the main battery feed, fusing and relay switching for the whole body, lighting and accessory harness. Instead of scattering separate fuse boxes and relay boxes around the cab and chassis, the OEM routes the body harness into one NBX-957, which keeps the wiring architecture clean and gives the service technician one place to find every fuse and relay.
The reference build carries 36 fused circuits and 25 relays across 15 body-electronics functions — from head/low-beam, fog, turn-signal and brake lamps to wipers, HVAC, cooling fans, power-window lift and the ECU ignition-on supply — inside an IP54 enclosure (IP65 variant available) rated 9–32 VDC and −40 to +85 °C, so one platform serves both 12 V and 24 V programmes. The exact circuit map, fuse ratings and relay count are quoted against your harness drawing.
Choosing the NBX-957 in the NBX family
The NBX-957 is the general-purpose body-central platform. Pick across the family by what actually drives your programme:
- Circuit count — for a deeper harness, step up to the NBX-970 (42-way) or NBX-953 (47-way); for a lighter harness, the NBX-958 (32-way) is sized down.
- Sealed / outdoor placement — if the box must sit outside the protected body cavity, choose the IP67 NBX-971 instead.
- On-board CAN body-control logic — if you need centralised body control rather than passive distribution, see the CAN-integrated NBX-952.
For the upstream architecture decision — whether your programme needs a central PDB at all, versus separate fuse, relay and junction boxes — see the power distribution buyer guide and the relay box vs fuse box vs junction box comparison.
Engineering details
Electrically, the NBX-957 supports 9–32 VDC operation and a working temperature range of −40 to +85 °C. The fuse mix and relay configuration are selected per program — typical builds combine ATO/ATC blade fuses with mini-relays for body actuators (wipers, lamps, fans, motors), plus dedicated higher‑current circuits for the cabin power supply.
- Configurable circuit map per program — fuse rating, relay count and connector pin-out are quoted against your harness drawing
- Reverse-polarity protection on the main power inputs — tolerates harness reconnection in field service
- Sealed split-housing option for chassis-near applications; standard variant for body cavity installation
- OEM-grade automotive connectors (Bussmann, Tyco/AMP, Delphi) with matching wire-side seals
Mechanical layout
Mating connectors
Current-production NBX-957 housings include 13 OEM-grade automotive connectors from KET, Tyco/AMP and THB. The reference P/N below documents the connectors on the current production build; the matching wire-side seals, terminal P/N and harness colour code are confirmed against the customer harness drawing at quotation.
| ID | Reference P/N | Brand |
|---|---|---|
| A | MG613689 | KET |
| B | 368457-1 | Tyco/AMP |
| C | MG610557 | KET |
| D | 936372-1 | Tyco/AMP |
| E | 936363-1 | Tyco/AMP |
| F | DJ7171-3-21 | generic / 3rd-party |
| G | 0329901 | THB |
| H | 368497-1 | Tyco/AMP |
| J | 936095-1 | Tyco/AMP |
| K | 0329701 | THB |
| L | 368451-1 | Tyco/AMP |
| M | MG610658 | KET |
| N | 368454-1 | Tyco/AMP |
Fuse & relay configuration
Standard NBX-957 build, customised on a programme basis:
| # | Component | Spec | Qty |
|---|---|---|---|
| 1 | Relay | ISO mini relay | 25 |
| 2 | Fuse | ATO/ATC blade fuse | 36 |
| 3 | Fuse (spare) | ATO/ATC blade fuse | 7 |
| 4 | Fuse-removal tool | — | 1 |
| 5 | Optional add-ons | Wiper interrupt module, flasher relay, water/temperature sensor, buzzer | per programme |
| 6 | Function customisation | Per circuit-diagram changes | — |
Built-in load functions
Programme-specific load mix — the NBX-957 standard reference build covers the following 15 vehicle-electronics functions:
- High & low-beam control
- Position / side-lamp control
- Fog-lamp control
- Turn signal & hazard flasher control
- Wiper control
- Brake-lamp control
- Horn control
- Power-window lift control
- Air-conditioning (HVAC) control
- Reverse / rear-lamp control
- Diagnostic interface
- ECU “ignition-on” supply control
- Cooling-fan control
- Tipping / lift control
- After-treatment heater control
Manufacturing & testing
Built under IATF 16949, with APQP project planning and a PPAP package available for OEM programs. End-of-line functional test before packaging; environmental validation and EMC pre-compliance screening in our in-house lab when the program requires it.
Related models & how to ask
Closely related models in the NBX series include the NBX-953 (47-circuit variant), NBX-970 (42-circuit) and NBX-958 (32-circuit) for higher and lower channel-count programs. For programs that require IP67 sealing, see the NBX-971 waterproof variant. To request drawings or BOM, please use the contact page.
