What Is Blackout Lighting on a Vehicle?
What is blackout lighting on a vehicle? It is a second, deliberately weak lighting system fitted to military vehicles alongside the normal service lights. It gives the driver just enough light to follow the route and the next vehicle enough to hold its interval, while showing as little as possible to an observer on the ground or in the air.
A complete set has four lamp types: front blackout markers, a blackout drive light, rear blackout markers and blackout stop lamps, all energised from the vehicle’s main light switch. This article explains what each lamp does, how the switch modes work, what the standards require and what to state when you specify blackout lighting for a platform.
Why Military Vehicles Need a Second Lighting System
Service lighting is designed to be seen from as far away as possible. Blackout lighting reverses that aim. A column moving at night under light discipline has to hide its position, its size and its direction of travel, and every lamp on a vehicle is a potential signature.
The drivers still have to see the road, and each of them has to know where the vehicle in front is and when it brakes. Blackout lighting meets those needs with the least light that will do the job: a low, downward drive light, small marker lamps that carry meaning only at short range, and a stop lamp that tells the following driver the vehicle ahead is slowing. A convoy can then keep formation and drive safely in darkness without lighting up its route for anyone watching.
The blackout lamps work alongside the service lights rather than replacing them. The vehicle keeps its normal headlamps, tail and stop lamps and indicators, and the main light switch decides which set is live.
What Each Blackout Lamp Does
US Army maintenance manuals describe the blackout lighting system as front blackout marker lights, a blackout drive light, rear blackout marker lights and blackout stop lights (TM 9-2320-365-34-1, Figure 1-12). NATO nations use the same four functions. The Czech defence standard ČOS 254001, which implements STANAG 4381, sets their mounting height, colour and light output as follows.
| Lamp | Recommended mounting | Colour | What it is for |
|---|---|---|---|
| Front blackout marker (6.2.5) | 380 to 1830 mm above the road | Amber (CIE x 0.596, y 0.406) | Marks the front of the vehicle for oncoming drivers and lets the driver ahead see that a vehicle is following. |
| Blackout drive light (6.2.4) | About 1060 mm; a single lamp preferably in line with the driver’s seat | Blue or blue-green lens | Lights the road for the driver: 0 cd on the reference axis and no more than 5 to 25 cd between 1° and 8° below it. |
| Rear blackout marker (6.2.6) | 380 to 1830 mm above the road | Red (CIE x 0.712, y 0.288) | Shows the following driver where the vehicle is and, through four separate apertures, how far away it is. |
| Blackout stop lamp (6.2.7) | 380 to 1830 mm above the road | Amber (CIE x 0.599, y 0.401) | Signals braking to the following driver through one circular aperture. |
The low figures for the drive light are the point. Its beam is held to a few candela and carries nothing on the reference axis, so the light is aimed down at the road ahead instead of out towards an observer. LED drive lamps with a blue-green output, such as our cyan blackout driving light, are listed against MIL-PRF-32215A, the US specification that covers an LED infrared secure blackout front driving lamp.
Blackout Marker Lights and the Cat’s Eyes Pattern
The rear blackout marker is the lamp a following driver watches all night, and it does more than show that a vehicle is there. Its light leaves through four small, separate windows. Close up, the eye resolves four spots. Further back they merge into two, and at longer range into one. Drivers call the pattern cat’s eyes, and it lets them judge their interval without any other reference.
The same clause sets the test: the observer approaches and backs away from a lamp mounted 1 m above the ground, or fitted to the vehicle, and the result is the average of three series of observations. A stand-alone lamp is tested with its bulb supplied at 28 V, and a vehicle with its engine at idle.
US driver training applies the same principle with a wider band. FM 21-305, as cited in published summaries, gives a correct following distance of 60 to 180 feet (about 18 to 55 m), at which the rear blackout markers appear as two red lights; closer, the driver sees four, and further back only one.
The front blackout markers use a simpler version of the idea. Under ČOS 254001 a stand-alone front marker shows two separate shapes, preferably Y-shaped, that merge into a single spot beyond a set distance. That distance is left blank in the published Czech text, so take it from the STANAG or national document your contract names.
Blackout Drive: How the Light Switch Selects Each Mode
Blackout lighting only works if the wrong lamps cannot come on. That is why the main light switch on a tactical vehicle is more than an on and off control. The operator’s manual TM 9-2320-365-10 describes a main selector lever with these positions:
- OFF: no exterior lights operate.
- BO MARKER: the blackout marker lights operate.
- BO DRIVE: all blackout lights operate, including the blackout drive light.
- STOP LIGHT: the stop lights operate when the brake pedal is pressed.
- SER DRIVE: all service drive lights operate.
An UNLOCK lever must be lifted and held to move the selector to any position except BO MARKER, and the parking lights work only with the selector at SER DRIVE. The lock means a driver under blackout conditions cannot switch the service lights on by accident with a single movement.
ČOS 254001 states the same requirement in general terms (clause 6.2.3). The switch must be within the driver’s reach and have three basic positions: normal exterior lighting, all exterior lighting off, and tactical exterior lighting. In the tactical position no prohibited light may come on, directly or indirectly. The tactical position also needs a sub-position for blackout driving with night vision devices, in which only the lights permitted for that purpose can be switched on.
For an integrator, the switch logic matters as much as the lamps. Every blackout lamp has to be wired so that it is live only in the positions that the vehicle manual or the contract specification allows.
Colour, Intensity and the Infrared Limit
Blackout lighting is often described as compatible with night vision, and that needs care. A blackout lamp is a visible lamp. Image intensifier tubes with gallium arsenide photocathodes are highly sensitive from about 450 to 950 nm, which covers the visible band and the near infrared. A lamp that looks dim to the eye but leaks near-infrared energy can therefore stand out through night vision goggles.
ČOS 254001 closes that gap. Clause 6.1.15 states that tactical lighting must not contain an infrared component: the peak emission between 700 and 1200 nm may be no more than 1 per cent of the peak measured in the visible band, 380 to 700 nm. The lens of the blackout drive light must meet the same limit (6.2.4 c), and clause 6.1.5 adds that the lighting must not restrict the use of the night vision devices in service. The US performance specifications use the term infrared secure for the same aim.
Infrared lamps are a different tool. They emit outside the visible band and are seen only through night vision equipment; infrared vehicle lighting explains how they are used. Some markers are offered in infrared versions as well, for example the blackout rear and stop marker with 850 nm and 940 nm options, so state clearly whether a vehicle needs a visible blackout function, an infrared function or both.
The Standards Behind Blackout Lighting
NATO’s agreement is STANAG 4381, Blackout Lighting Systems for Tactical Land Vehicles. Its aim is to guide member nations in the design and application of blackout lighting systems on tactical land vehicles. The STANAG text is not public, so nations publish their own documents. ČOS 254001 implements Edition 2 together with AEP-4381(A)(1). In Germany, VG 96945-5:2023-04 is the detail standard for the blackout stop lamp and blackout rear lamp.
In the United States, three military performance specifications, all dated 12 March 2009, cover LED blackout lamps:
- MIL-PRF-32212A: LED composite stop, rear turn signal and tail lamps with infrared secure blackout tail and blackout stop lamps.
- MIL-PRF-32214: LED composite front park and turn signal lamp with infrared secure front blackout marker lamp.
- MIL-PRF-32215A: LED infrared secure blackout front driving lamp.
Two of the three combine blackout functions with service functions in one composite lamp. Combining them saves space on a crowded hull or rear panel, and it is why the switch logic described above belongs in the lamp specification.
What to State When Specifying Blackout Lighting
A clear enquiry saves a round of questions. These are the points that decide which lamps fit a platform:
- Governing document: the STANAG 4381 edition, the national implementation (such as ČOS 254001 or a VG standard) or the MIL-PRF specification, with its revision letter.
- Vehicle type: wheeled or tracked, because the number of lamps required differs.
- Supply voltage: state the vehicle’s system voltage. The rear and stop marker and the cyan drive light, for example, are listed for 24 V DC.
- Infrared: infrared secure visible lamps, an infrared version (850 nm or 940 nm), or both.
- Switch integration: which switch positions each lamp must be live in, including any night vision sub-position.
- Dedicated or combined lamps: separate blackout lamps, or composite lamps that carry service and blackout functions in one housing.
- Connector and mounting: the rear and stop marker and the cyan drive light use Deutsch DT04-2P / DT06-2S connectors and flange mounting; state your harness connector if it differs.
The full range of military blackout lights lists the voltage, connector and standards for each lamp, and we build to specification where a platform needs something the catalogue does not carry.
Frequently Asked Questions
Under ČOS 254001 a wheeled vehicle carries two of each: two blackout drive lights, two front markers, two rear markers and two stop lamps. A tracked vehicle needs at least one drive light, at least one rear marker and at least one stop lamp, and front markers are not prescribed. US vehicles usually carry a single blackout drive light on the driver’s side, on the fender or grille. Check the document your contract names, because counts and positions can differ between nations and editions.
Yes. MIL-PRF-32212A, for example, is written for exactly that design: a composite LED rear lamp with blackout tail and blackout stop functions. Two points deserve a check when the blackout tail and stop functions share a housing. ČOS 254001 clause 6.2.7 d) requires their light spots to be distinguishable from each other at 100 m or more, so the following driver can still tell braking from the marker. And the wiring must make it impossible to light a service function while the switch is in the tactical position.
The lamps can be fitted, but the switching should not be skipped. A separate toggle for the blackout lamps alone does not stop a driver turning the service lights on under blackout conditions, which is exactly what the locked main switch exists to prevent. A proper retrofit therefore covers the lamps, a multi-position switch within the driver’s reach and the harness changes that tie them together. Send us the vehicle type and its existing switch and we will advise on the parts.
The edition dated 8 July 1994 is listed as inactive in public standards databases, but the agreement continues in Edition 2 with AEP-4381(A)(1), which the Czech ČOS 254001 implements in a change that came into force on 5 November 2025. If a specification cites STANAG 4381 without an edition, query it with the contracting authority before lamps are selected, and ask which national implementation applies.