17 years ago
I work in the trailer manufacturing business.
We use LED tail-light clusters.
The modern truck/tractors utilise a computer system to perform diagnostics
on various systems within the rig. One of these is the lighting system.
A pulse is sent to each tail light, the system monitoring the current. If
there is current flow, it is assumed the incandescent globes are OK.
Unfortunately, the LED lamps draw such a small amount of current that the
computer does not see a "filament" and flags a major fault on the truck
dashboard. In addition to the error message, the system continues to send
curent pulss in the forlorn hope that things at the rear of the rig have
improved. This causes the entire suite of LED lamps to flash like a
There are ways around it. Some manufacturers have placed incandescent globes
in parallel with the LED lamps, others have used high wattage resistors.
Neither is acceptable for obvious reasons.
There must be a way to "tell" the computer that the LED lamps are fine by
emulating the current drawn by an incandescent globe, without using the
solutions noted above.
Do any of you outstandingly brilliant contributors have any novel and