2019 Peterbilt 579 Bulb Size Guide

Quick reference

LED vs halogen upgrade considerations

Upgrading your 2019 Peterbilt 579 to LED bulbs can provide brighter, longer-lasting light. However, there are a few things to consider before making the switch. CANBUS errors are a common issue when upgrading to LEDs. This is because LED bulbs draw less power than halogen bulbs, which can cause the truck's computer to think that a bulb is burned out. To avoid this, you may need to install a load resistor or use CANBUS-compatible LED bulbs. You may also need adapters to fit the LED bulbs into the factory sockets.

How to replace each bulb

Low Beam Headlight: The low beam headlight is located in the main headlight housing. To replace it, you will need to open the hood and access the back of the headlight assembly. The bulb is held in place by a retaining ring. Twist the ring counter-clockwise to remove it, then pull the bulb out.

High Beam Headlight: The high beam headlight is also located in the main headlight housing. To replace it, you will need to open the hood and access the back of the headlight assembly. The bulb is held in place by a retaining ring. Twist the ring counter-clockwise to remove it, then pull the bulb out.

Fog Light: The fog light is located in the front bumper. To replace it, you will need to access the back of the fog light assembly from underneath the truck. The bulb is held in place by a retaining ring. Twist the ring counter-clockwise to remove it, then pull the bulb out.

Daytime Running Light (DRL): The DRL is located in the main headlight housing. To replace it, you will need to open the hood and access the back of the headlight assembly. The bulb is held in place by a retaining ring. Twist the ring counter-clockwise to remove it, then pull the bulb out.

Front Turn Signal: The front turn signal is located in the main headlight housing. To replace it, you will need to open the hood and access the back of the headlight assembly. The bulb is held in place by a socket. Twist the socket counter-clockwise to remove it, then pull the bulb out.

Rear Turn Signal: The rear turn signal is located in the tail light assembly. To replace it, you will need to remove the tail light assembly from the truck. The assembly is held in place by two screws. Once the screws are removed, you can pull the assembly out and access the back. The bulb is held in place by a socket. Twist the socket counter-clockwise to remove it, then pull the bulb out.

Brake Light: The brake light is located in the tail light assembly. To replace it, you will need to remove the tail light assembly from the truck. The assembly is held in place by two screws. Once the screws are removed, you can pull the assembly out and access the back. The bulb is held in place by a socket. Twist the socket counter-clockwise to remove it, then pull the bulb out.

Tail Light: The tail light is located in the tail light assembly. To replace it, you will need to remove the tail light assembly from the truck. The assembly is held in place by two screws. Once the screws are removed, you can pull the assembly out and access the back. The bulb is held in place by a socket. Twist the socket counter-clockwise to remove it, then pull the bulb out.

Reverse Light: The reverse light is located in the tail light assembly. To replace it, you will need to remove the tail light assembly from the truck. The assembly is held in place by two screws. Once the screws are removed, you can pull the assembly out and access the back. The bulb is held in place by a socket. Twist the socket counter-clockwise to remove it, then pull the bulb out.

License Plate Light: The license plate light is located on the rear of the truck, above the license plate. To replace it, you will need to remove the two screws that hold the lens in place. Once the lens is removed, you can access the bulb. The bulb is held in place by a socket. Pull the bulb out of the socket and replace it with a new one.

Side Marker Light: The side marker light is located on the side of the truck, near the front wheel. To replace it, you will need to remove the two screws that hold the lens in place. Once the lens is removed, you can access the bulb. The bulb is held in place by a socket. Pull the bulb out of the socket and replace it with a new one.

Dome/Map Light: The dome/map light is located in the cab of the truck, on the ceiling. To replace it, you will need to pry the lens off with a small screwdriver. Once the lens is removed, you can access the bulb. The bulb is held in place by two clips. Pry the clips apart and remove the bulb.

Common lighting issues for this generation

One of the most common lighting issues for the 2019 Peterbilt 579 is premature bulb burnout. This is often caused by vibration from the engine and road. To help prevent this, you can use heavy-duty bulbs that are designed to withstand vibration. Another common issue is moisture in the headlight housings. This can cause the bulbs to short out or fail prematurely. To prevent this, make sure that the headlight housings are properly sealed.

Find a trusted shop on Repairius.