2019 aftermarket LED Taillight bulb issue

[Learylax3r]

My friend purchased some LED Taillight bulbs from Diode Dynamics and while they worked originally, the tail light function stopped working. The brake lights still illuminate just fine. I helped him with the install because I have AlfaOBD. He has the security bypass module and other swapped LEDs work fine on the truck. There is no bulb out warning on the dash, but alfa sees a trouble code for a short circuit to ground on the left tail light, the DTC bypass was not selected. When he put the stock halogen tail lights back in, everything worked as it should.

My question is, what would cause this issue with the LED bulbs, is there a separate voltage for brake vs running tail light like the parking/turn signals or are they separate circuits entirely?

Thanks in advance for your input

 

[danielmid]

Is it both L and R bulbs or just one side not working for running lights?

 

[Learylax3r]

Both sides

 

[danielmid]

Checked fuses?

 

[Learylax3r]

The fuses I checked looked good, I couldn't find one that specifically said tail lights, but I checked the trailer tails and exterior lights fuses, plus the original halogen bulbs worked as normal when put back in, so I think I can rule out a fuse

 

[danielmid]

The fuses I checked looked good, I couldn't find one that specifically said tail lights, but I checked the trailer tails and exterior lights fuses, plus the original halogen bulbs worked as normal when put back in, so I think I can rule out a fuse

I think you've narrowed it down to bad/incompatible bulbs.