Skip the auto shop - Our mechanics make house calls

How Do Underbody Car Lights Work?

underbody lights
Michael Stokes /

Your car has a number of important lights on it – headlights, turn signals, taillights, brake lights, running lights, and more. However, your options aren’t limited to what was installed by the automaker. You can install aftermarket taillights and lenses, different headlights and more. That includes underbody car lights – also called glow lights. These come in a wide range of colors and provide a cool glow under your car while it’s driving. How do they work?

Types on the market

There are two primary types of underbody car lights available – fluorescent bulbs, which are the older of the two, and becoming rarer these days – and LED light strips. These are newer, and are becoming the norm for the industry.

Both types are mounted under the car, generally to the underside of the frame. Most of the time, they must be attached with zip ties. Once the strip is installed, it must be wired. This requires a module box and electrical wires. The box is usually mounted near the front of the car, and will connect to the light strips in one of two ways.

The older method required an individual connection to each strip, which meant running four sets of wires under your car (one for each light strip as they’re generally installed on both the left and right sides, as well as the front and rear). A newer method allows them to be connected in series, so the module would connect to the front light strip, then that strip would connect to the second, and so on.

The module box is wired directly to the car’s battery for power (and is usually mounted on top of the engine). Most systems are operated directly from the module box, so there’s no need to splice into your headlight switch. A remote allows you to activate the lights from inside the car.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.


Post a question and get free advice from our certified mechanics.


More related articles

P0222 OBD-II Trouble Code: Throttle/Pedal Position Switch/Sensor B Circuit Low Input
P0222 code definition Throttle/Pedal Position Switch/Sensor B Circuit Low Input What the P0222 code means The manufacturer specifies a range of acceptable voltage to be produced from the throttle position...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
How to Buy Fuel Treatments
Adding a fuel additive to your gas tank when you fill up is one way to clean vital engine parts of deposits, improve the performance of your engine,...

Related questions

Q: How Does Underbody Lighting on Cars Work?

Underbody lighting on cars is an accessory that is most commonly installed by the vehicle owner or a specialty shop. The type of underbody lights used today are either LED or neon, and are available in a variety of colors....

Q: Need help with roof rack on my car

Hello. I’m not sure if there is an aftermarket part/attachment for the anchor points. I would suggest that you contact the dealer to see if they make this type of attachment, or a different type of roof rack that can...

Q: How do I use the rear reading lights?

The rear reading lights double as courtesy lights when you unlock your car. If you want to turn them on for added interior visibility, you can do so easily. First, locate the lights, which are in the rear passenger compartment....