Overview
The NBX‑2404 is a six-channel relay box that handles switched load distribution for body, lighting, wiper, fan, heater and auxiliary circuits. It is the right choice when the program already has a fuse box and needs dedicated relay switching, or when central distribution is split across multiple smaller units.
Engineering details
Electrically: 12 V / 24 V supply, −40 to +85 °C working range, six independent relay channels with reverse-polarity protection on the supply rail. Common-rail layout is configurable.
- 6 independent relay channels for switched load distribution
- Reverse-polarity protection on the supply rail
- Modular layout — pairs with NBX‑955 / NBX‑981 / NBX‑2301 fuse boxes
- Compact mechanical footprint for protected cabin or in-enclosure placement
Mechanical layout
Mating connectors
The standard NBX-2404 build uses 4 colour-coded harness-side connectors, each an 8-pin sealed housing, plus an M8 power-stud for the main supply. Wire-side seals, terminal P/N and pin-out are confirmed against the customer harness drawing at quotation.
| # | Colour | Connector P/N | Pin count |
|---|---|---|---|
| 1 | Black | 1518302 | 8 |
| 2 | Grey | 1518303 | 8 |
| 3 | Blue | 1518304 | 8 |
| 4 | Green | 1518301 | 8 |
| — | — | M8 power-stud | main supply |
Relay configuration
Standard build — 6 independent automotive relays wired to the 4 colour-coded connectors per the manual electrical schematic. Each relay channel can be sized for switched, ignition-controlled or accessory loads on a programme basis.
- 6 relay channels with reverse-polarity protection on the supply rail
- Channel-to-pin mapping defined per programme harness drawing
- Compact footprint pairs with NBX-955 / NBX-981 / NBX-2301 fuse boxes for combined fuse + relay distribution
Choosing a relay solution: dedicated NBX-2404, fuse-box relay sockets, or a central PDB
“I need relay switching” has three answers in the NBX family, and the right one depends on how many relays you need and whether they sit with the fuses or on their own:
- A few relays alongside the fusing, in one cabin panel — stay with the fuse box. The NBX-981 (15-way) and NBX-2301 (17-way) take optional ISO mini-relay sockets next to the fuse positions, so a handful of switched circuits need no separate enclosure.
- Dedicated switching, or switching kept physically separate from the fusing — this is the NBX-2404's job. Six independent relay channels in their own enclosure, sized for body, lighting, wiper, fan and heater loads, paired with an upstream fuse box that protects the wire — a relay box switches but does not protect, so the fuse always sits upstream.
- Many relays plus dense fusing, consolidated in one box — step up to the NBX-957 central PDB, whose reference build carries 25 relays and 36 fuses in a single body-central enclosure. When dedicated switching outgrows a single six-channel NBX-2404, the central PDB is usually cleaner than ganging multiple relay boxes.
For the underlying architecture decision — fuse box, relay box, junction box or central PDB — see the junction vs fuse vs relay box guide.
Manufacturing & testing
Manufactured under IATF 16949 with the same PPAP discipline as the rest of the NBX family.
Related models & how to ask
Pair with the NBX‑955 12-way, NBX‑981 15-way or NBX‑2301 17-way fuse box for a fuse + relay split architecture. If the program would prefer combined fusing and switching in one box, see NBX‑957. Drawings via the contact page.
