A tail light looks simpler than a headlight, but on a modern truck it can carry more than lights: a blind-spot module, or the hardware for an optional system. When you replace the lamp, the rule is the same one that decides headlights.
If the feature is a signal the vehicle sends to the tail light, it carries over. If the feature is hardware inside the factory lamp, it carries over only if the new lamp has it too, or it can be moved across.
The feature-by-feature answer
| Factory feature | After a RIGNOX tail light |
|---|---|
| Running lights, brake lights, reverse lights | Work, all on LED, so they light instantly and evenly. |
| Turn signals and hazards | Work. Most RIGNOX builds signal in amber with a sequential sweep; the product page says which. Built-in CANbus decoders plus included hyper-flash protection keep the flash at the factory rate, with no dash codes. |
| Blind-spot monitoring, sensor in the bumper | Unaffected. The tail light swap doesn't touch it. |
| Blind-spot monitoring, module in the tail light | Kept on builds the product page lists as BLIS-compatible: you move the module from the factory lamp to the RIGNOX housing during install. Builds marked Non-BLIS Only don't take the module. Where the module sits on your truck, and which build keeps it, is on the product page. |
| Options built into the factory lamp (for example, an onboard payload scale, or on a few trucks a heated lens) | Not carried over. These live inside the factory lamp; check the product page's Fits line ("all trims" means every trim with that factory tail light). |
| Features the factory saved for top trims | Added: sequential signals and a startup animation, on most builds, on any trim. |
See which RIGNOX tail light builds fit your vehicle and its factory setup.
Brake and turn at the same time: why one side flashes
Some vehicles light the brake signal and the turn signal through the same section of the lamp, which is common on trucks whose rear turn signals are red. On those vehicles, press the brake and signal at the same time, and the signaling side flashes while the other side stays lit as a brake light. With the hazards on, both sides flash. That isn't a fault: federal lighting rules (FMVSS 108, 49 CFR 571.108) require it. When a stop lamp and a turn signal share a lamp, the circuit must keep the brake signal from lighting on the side that is flashing. RIGNOX tail lights for these vehicles keep that behavior, the same as the factory lamp.
On vehicles where brake and turn are separate, both brake lights stay on and the turn signal flashes on its own.
To tell which kind you have, watch the factory lamp while signaling. If a red section flashes, brake and turn share a circuit. If a separate amber section flashes, they are separate.
Check before you order
- The back of the factory lamp. Bulb sockets or one multi-pin plug? Which one you have, and on plug-type lamps the pin count, decides the build. See the tail light buying guide.
- Your mirrors. A blind-spot warning light in the mirror means BLIS. Check the product page for BLIS-compatible builds.
- The product page's Fits line. Options built into the tail lights, such as an onboard payload scale, aren't carried over; check the Fits line ("all trims" means every trim with that factory tail light).
The short version
- Signals the vehicle sends (running, brake, turn, reverse, hazards) carry over, all on LED.
- A BLIS module in the tail light moves over on BLIS-compatible builds. A sensor in the bumper isn't affected.
- Options built into the factory lamp, such as an onboard payload scale, aren't carried over; check the product page's Fits line ("all trims" means every trim with that factory tail light).
- If brake and turn share a circuit, the signaling side flashes during braking. That is required by law, not a fault.
Related: Is this normal? · Not working? · Hyperflash and bulb-out warnings · Which headlight features carry over
