2014 Isuzu NQR Fuse Box Diagram, Locations, & Amperage

The 2014 Isuzu NQR is a rugged, reliable commercial cab-over truck trusted by fleets and independent operators alike. Whether you are dealing with a dead blower motor, inoperable headlights, or a silent radio, finding and checking the right fuse is the first step in electrical diagnostics.

Because the Isuzu N-Series often undergoes heavy upfitting (box trucks, flatbeds, dumps), it is crucial to understand the factory fuse layout while keeping in mind that body builders may add auxiliary fuse panels. Always verify with the printed legend inside your specific fuse box lid.

Quick answer: Where are the fuse boxes on a 2014 Isuzu NQR?

The 2014 Isuzu NQR features two primary factory fuse box locations:

• Interior Dash Fuse Box: Located inside the cab, typically behind a removable panel in the center of the dashboard or lower dash area (near the driver's left knee or center console depending on exact cab configuration).
• Exterior / Frame Fuse and Relay Box: Located outside the cab, usually mounted on the chassis frame rail near the battery box or just behind the cab. This box handles high-amperage components and exterior lighting.

Below are the most common configurations for the 2014 Isuzu NQR.

Interior Dash Fuse Box

The interior fuse block handles most of the cab’s accessories, climate control, and interior electronics.

Relays located near the interior panel typically include the Turn Signal/Hazard Flasher Relay, Blower Motor Relay, and Ignition Main Relay.

Exterior / Frame Fuse Box

The exterior fuse block handles heavy-duty circuits, engine management power, and exterior lighting systems. It is exposed to the elements, so ensure the cover is always securely latched.

Relays located in the exterior box typically include the Starter Relay, Fuel Pump Relay, Headlight Relays, Glow Plug Relay, and ECM Main Relay.

How to test a fuse

When an electrical component stops working on your NQR, testing the fuses is the fastest way to begin diagnosing the problem. Here is the ASE-certified method for checking fuses:

1. Visual Inspection: Pull the suspect fuse using fuse pullers or needle-nose pliers. Hold it up to the light. If the metal filament inside the plastic casing is melted or broken, the fuse is blown.
2. Use a Test Light: The most efficient way to check fuses without removing them is with a 12V test light. Turn the ignition switch to the "ON" position. Ground the test light clip to a bare metal surface. Touch the probe to the small metal test points on the top of the fuse. If the light illuminates on both sides, the fuse is good. If it only lights on one side, the fuse is blown.
3. Use a Multimeter: Set your digital multimeter to the continuity setting (the one that beeps). Touch a probe to each test point on top of the fuse. A continuous beep means the fuse is good. No beep means it has failed.
4. Never bypass a fuse: Never replace a blown fuse with a higher amperage rating or wrap it in aluminum foil. Doing so can cause severe wire harness damage or a vehicle fire.

Common blown fuses on this vehicle

Commercial trucks live hard lives, and the 2014 Isuzu NQR is no exception. If you are experiencing issues, check these common culprits first:

• Cigar Lighter / 12V Outlet (15A): Fleet drivers frequently plug in GPS units, phone chargers, and dashcams. Damaged accessory plugs often short out this circuit.
• Tail / Clearance Lights (15A): Box trucks and flatbeds have extensive aftermarket lighting wiring. Corrosion at the rear harness connections or physical damage to marker lights frequently blows this fuse.
• Blower Motor (20A): If the cabin climate control stops blowing air, check the 20A blower fuse and the associated relay. Blower motors draw high current as they age, which can eventually pop the fuse.
• Turn Signals / Flasher (15A): Similar to the clearance lights, trailer wiring and aftermarket truck body wiring can cause shorts in the turn signal circuit. Check the wiring at the rear of the frame rail if this fuse blows repeatedly.

If you are dealing with persistent electrical gremlins or a fuse that blows immediately upon replacement, you likely have a dead short in the wiring harness. Don't risk melting your truck's harness. Find a trusted shop on Repairius.