Working light

Work lights provide safe, focused illumination around the vehicle, load compartment, bodywork or work area. They are used on MAN TGL, TGM, TGA, TGS, TGX and TG3 trucks, TGE vans and MAN Lion’s City or Lion’s Coach buses, as well as on Mercedes Atego, Axor, Actros, Arocs, Econic, Sprinter, Vito and Citaro vehicles. Depending on the application, these may include reversing work lights, work lamps on the chassis or cargo body, cab work lights, roof-mounted driving lights or LED work lamps on crane, tipper and service bodies, for example. Neoplan coaches may also use specific work or manoeuvring lights.

The correct selection must always be made based on the chassis number. Visual comparison, a matching connector or selection based solely on the model name is never sufficient. Specification, year of manufacture, original wiring harness, control via a body ECU, voltage level and mounting position may vary within a single vehicle series.

Work lights are available in halogen, xenon and, above all, LED versions. Halogen lamps generate more heat and have a relatively high current draw, whereas LED work lights generally place less electrical load on the system for comparable light output. Pay attention not only to the nominal voltage of 12 V or 24 V, but also to the actual voltage range, resistance to voltage spikes and EMC compatibility. On modern vehicles with CAN bus monitoring, an unsuitable LED unit may cause a lamp failure warning, flashing lights or a fault code in the body control unit.

Key selection parameters include beam pattern, luminous flux in lumens, colour temperature, IP protection rating, connector version, cable length and mounting method. A wide flood beam, also known as a wide-beam light, is suitable for tail lifts and nearby work areas; a spot beam concentrates the light for visibility over greater distances. For mounting low on the chassis, a high IP rating, impact-resistant polycarbonate lens, aluminium housing with corrosion-resistant coating and a vibration-resistant bracket are essential. Also check the fit of the mounting bolt, the centre distance between mounting holes and the available space behind the lamp.

Common fault symptoms include complete failure, flickering caused by vibrations, weak light output, moisture behind the lens, melted connector housings and repeatedly blown fuses. In LED work lights, internal electronics can be damaged by voltage spikes, incorrectly connected polarity or water ingress. In halogen versions, burnt lamp holders, oxidised contacts and heat stress often cause contact resistance. As a result, the voltage drops under load and the lamp burns noticeably dimmer.

Start with a visual inspection of the lens, housing, cable sheath, cable entry and mounting bracket. Then check the fuse rating and the switching or control relay. Use a multimeter to measure the supply voltage directly at the connector while the work light is switched on. In a 24 V system, the voltage drop between the battery positive terminal and the positive connection, as well as between the negative connection and the earth point, must remain limited under load. Excessive voltage drop indicates corroded cable terminals, damaged conductors, poor earth connection or an inadequately sized cable cross-section.

Then measure the earth connection using a voltage drop test rather than only a continuity test: a cable may appear sound without load but still show resistance when current is drawn. On LED units, also check whether the vehicle control unit activates an output and whether a PWM-controlled signal is present. Repair damaged cables using correctly crimped, sealed connections and protect the wiring harness from chafing against chassis or bodywork components.

Replace a work light when the lens is cracked, the housing allows water ingress, the LED circuit board fails intermittently or the reflector has been affected by heat. Fit the new lamp with the power disconnected, use the specified fuse rating and observe the polarity. Route cables with sufficient slack to accommodate vibrations, but without loose loops that can chafe. Fit mounting bolts with the correct locking method and adjust the beam pattern so that the work area is illuminated without dazzling other road users.

For an efficient repair, technically checked components and correct identification are decisive. Braem supports this with technical expertise and a wide range of lighting for professional applications.