2019 Isuzu NQR Bulb Sizes

Quick reference

The 2019 Isuzu NQR, a versatile medium-duty truck, primarily utilizes halogen bulbs across its lighting system. Unlike many passenger vehicles, the NQR typically does not offer factory LED headlight options or HID/projector systems, simplifying bulb replacement for owners and technicians. All listed sizes refer to the standard halogen fitments found on most NQR models for this year.

LED vs halogen upgrade considerations

While the 2019 Isuzu NQR comes equipped with a full suite of halogen bulbs, upgrading to LED replacements can offer several advantages, including brighter illumination, longer lifespan, and a more modern appearance. However, there are important considerations for a successful LED conversion:

• CANBUS Errors: Modern vehicles, including the NQR, often use a CANBUS (Controller Area Network Bus) system to monitor electrical circuits. Halogen bulbs draw more power than LEDs. When you replace a halogen bulb with an LED, the lower power draw can be interpreted by the CANBUS system as a "bulb out" error, leading to flickering, partial illumination, or dashboard warning lights. To prevent this, CANBUS-compatible LED bulbs or load resistors (decoders) are often required. Load resistors mimic the power draw of a halogen bulb, tricking the CANBUS system into recognizing the LED as a valid bulb.
• Adapters Needed: For some LED applications, especially in headlights, you might need specific mounting adapters to properly seat the LED bulb into the factory housing. The base of an LED bulb can sometimes be larger than a traditional halogen, requiring an adapter to ensure a secure fit and correct beam pattern.
• Beam Pattern and Glare: LED headlights produce light differently than halogens. Simply installing LED bulbs into housings designed for halogens can result in a scattered beam pattern, reduced visibility, and excessive glare for oncoming drivers. For optimal performance and safety, it's crucial to choose LED bulbs specifically designed to mimic the beam pattern of their halogen counterparts or consider projector-style LED housings if available for your NQR.
• Heat Dissipation: LEDs generate heat, but unlike halogens which radiate heat forward, LEDs dissipate heat from their base. High-quality LED bulbs feature integrated cooling fans or heatsinks to manage this. Ensure adequate space around the bulb for proper heat dissipation to prevent premature failure.

How to replace each bulb

Replacing bulbs on your 2019 Isuzu NQR is generally straightforward, but access can vary. Always ensure the vehicle is off and the lights are cool before attempting replacement.

• Low Beam Headlight (H9): Access is typically from behind the headlight assembly, often requiring removal of a rubber dust cover. Twist and remove the old bulb, then install the new one, ensuring it's seated correctly.
• High Beam Headlight (H7): Similar to the low beam, access is usually from the rear of the headlight housing. Disconnect the electrical connector, unclip the bulb, and replace.
• Fog Light (H11): These are usually located in the bumper and may require reaching underneath the vehicle or removing a trim panel for access. Turn the bulb counter-clockwise to remove.
• DRL (1157NA): Typically part of the front turn signal housing. Access may be from the back of the housing.
• Front Turn Signal (3157/3157NA): Access the bulb socket from the rear of the headlight or turn signal assembly. Twist the socket to remove, then pull the old bulb straight out.
• Rear Turn Signal (1156): Access is usually from inside the rear light assembly, often requiring removal of the lens cover or a panel in the cargo area. Twist the socket to remove.
• Brake Light (1157): Integrated into the rear tail light assembly. Access is from behind the light housing, often by removing the lens.
• Tail Light (1157): Shares the same bulb and access as the brake light.
• Reverse Light (921): Located in the rear light assembly. Access is from behind the light housing. Twist the socket and pull the bulb.
• License Plate (194): Usually a small housing above the license plate. Often requires removing a small screw or prying off a plastic cover.
• Side Marker (194): These small bulbs are typically found on the side of the truck or fender. Access usually involves gently prying out the lens assembly.
• Dome/Map Light (194): Typically covered by a clear or frosted plastic lens in the cabin. Use a small flat-head screwdriver or plastic pry tool to carefully remove the lens to access the bulb.

Common lighting issues for this generation

For the 2019 Isuzu NQR, common lighting issues are generally related to the lifespan of halogen bulbs and the demands of commercial operation:

• Frequent Bulb Burnouts: Due to long operating hours and vibrations common in commercial trucks, halogen bulbs can burn out more frequently than in passenger cars. Keep spare bulbs on hand, especially for critical lights like headlights and turn signals.
• Corrosion in Sockets: Exposure to elements and road grime can lead to corrosion in bulb sockets, causing intermittent operation or complete failure. Inspect sockets for corrosion during bulb replacement and clean with electrical contact cleaner if necessary.
• Wiring Harness Issues: While less common, chaffed or damaged wiring harnesses can cause lighting malfunctions. If a bulb replacement doesn't solve a problem, inspect the relevant wiring for signs of damage.
• DRL Malfunctions: Issues with Daytime Running Lights can sometimes be traced to electrical relays or the DRL module itself, rather than just the bulb.

Regular inspection of all lights – headlights, tail lights, turn signals, and interior lights – is recommended to ensure safety and compliance.

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