Fleet & Auto Reference Library · Technical Reference

Work Lights & Off-Road Lamps

Work lights and off-road lamps light job sites, equipment and the area around a vehicle, and most are not approved for use on public roads. This sheet covers beam patterns, the specs to compare and the rules that keep them from being used as road lamps.

Ref FA-0021

Draft, open for review. Check every value against the governing standard and the manufacturer’s data before use.

What it is

Work lights and off-road lamps are auxiliary lamps added to trucks, tractors, construction equipment, service bodies and trailers. They include flood lamps for close area light, spot lamps for distance, combination pattern bars, scene lights and rear work lights. They are not headlamps, fog lamps or other lamps required by FMVSS 108, and most are not designed to meet it. Many are labeled "for off-road use only." State laws limit when auxiliary lamps may be lit on the road, and many require them to be covered or switched off.

How to identify

Read the housing label and package. Look for the beam pattern, input voltage range, current draw, lumen rating, ingress protection (IP) rating and any SAE or DOT markings. A lamp marked "off-road use only" or with no DOT or SAE function code is not a road lamp. LED work lights usually run on a range of voltages so they fit 12 V and 24 V systems. Check the label for the actual range.

Beam patterns

Pattern	Light shape	Typical use	Notes
Flood	Wide and short	Work area around the vehicle	Most common rear and side work light
Spot	Narrow and long	Distance lighting off-road	Glare risk to others
Combo	Spot center with flood sides	Light bars	Off-road use only in most cases
Trapezoid or wide flood	Wide even field	Loaders, ag equipment	Less hot spot
Scene light	Very wide, high mount	Emergency and utility scenes	Often high current draw
Fog lamp (SAE marked)	Wide and low with sharp cutoff	Road use in fog where permitted	A road lamp only if marked for the function

Key points

Lumens show output, not usefulness. Beam pattern and mounting position matter as much.
IP ratings such as IP67, IP68 or IP69K describe dust and water resistance. Pressure-wash equipment needs the higher ratings.
LED lamps can cause radio interference. Ask whether the lamp meets an EMC standard if the customer uses two-way radios.
Wire the lamp through a relay and fused circuit sized from the lamp maker's data and the vehicle maker's guidance.
Rear work lights should be wired so they cannot be mistaken for backup or tail lamps.

Common mistakes

Selling a spot pattern light bar as a road headlamp upgrade.
Mounting a work light where it shines into the cab or mirrors.
Choosing a lamp by lumen claim alone.
Tapping into the headlamp circuit instead of a dedicated relay circuit.

Governing standards: No single federal standard for off-road work lamps; FMVSS 108 governs required road lamps. State vehicle codes govern auxiliary lamp use. IEC 60529 for IP codes.

Reference only. Verify against the current governing code or standard, the manufacturer's data and the project documents before use. Apps for Distributors disclaims liability arising from reliance on this reference.

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