2016 Kenworth T680 Bulb Size Guide

Quick Reference Bulb Size Chart

Note: Higher trim levels of the 2016 Kenworth T680 were available with factory-installed LED headlights. Base models typically came with halogen bulbs. Always double-check your existing bulbs before purchasing replacements.

LED vs. Halogen Upgrade Considerations

Upgrading your 2016 Kenworth T680 to LED bulbs can provide brighter, longer-lasting light. However, there are a few things to keep in mind:

• CANBUS Errors: The T680's computer system is designed to work with halogen bulbs. Because LED bulbs use less power, the system may think a bulb is burned out, which can cause a "bulb out" warning on your dashboard. To fix this, you may need to install a CANBUS-compatible LED bulb or an in-line resistor.
• Adapters: Some LED bulbs may require an adapter to fit correctly in the stock housing. This is especially true for the headlights. Make sure to check if the LED kit you are purchasing includes the necessary adapters for your T680.
• Headlight Housings: The 2016 T680 came with both projector and reflector headlight housings. Projector housings, which were standard on higher trims, work well with both halogen and LED bulbs. Reflector housings may not provide an ideal beam pattern with some LED bulbs, potentially causing glare for oncoming drivers. If you have reflector housings, look for LED bulbs specifically designed for them.

How to Replace Each Bulb

• Headlights (Low and High Beam): Access the headlight housing from the front of the truck. The bulb sockets are at the back of the housing. Turn the socket counter-clockwise to remove it, then replace the bulb.
• Fog Lights: The fog lights are located in the lower bumper. You will need to access them from underneath the truck. The bulb replacement process is similar to the headlights.
• Turn Signals, Brake Lights, and Tail Lights: These bulbs are all located in the same housing at the rear of the truck. You will need to remove the lens to access the bulbs.
• Reverse Lights: The reverse lights are also in the rear housing, and are replaced in the same way as the other rear bulbs.
• License Plate Lights: These small bulbs are located above the license plate. You can usually pop the lens off with a small screwdriver to access the bulb.
• Side Marker Lights: The side marker lights are on the sides of the cab and sleeper. The lenses can be removed to access the bulbs for replacement.
• Interior Dome/Map Lights: The dome and map lights are in the overhead console. The lenses can be carefully pried off to reveal the bulbs.

Common Lighting Issues for this Generation

The 2016 Kenworth T680 is a reliable truck, but a few lighting issues have been reported:

• Premature Bulb Burnout: Some owners have reported that the halogen headlights burn out prematurely. This can be caused by voltage spikes in the electrical system. Installing a quality surge protector can help to extend the life of your bulbs.
• Condensation in Headlight Housings: Over time, the seals on the headlight housings can fail, allowing moisture to get inside. This can cause the bulbs to short out and can also damage the reflective surfaces inside the housing. If you notice condensation in your headlights, it is best to have them resealed or replaced.

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