Our dash light came on indicating a rear tail light problem. Testing showed the outer left brake light was working when the headlights (and rear running lights) were off, but when the running light was on, the brake light didn’t work. I thought that must be insufficient grounding as they’re in the same bulb.

I removed the bulb socket, cleaned the ground pin connection and even bent the ground pin.
That worked for quite a while and eventually failed. The ground pin just had little tension.

I measured the current draw on the bulb filaments. The brake light draws 2.14 amps while the running light draws 0.53 amps. Evidently the ground pin could not sink 2.67 amps.

I tried to replace the socket and got one from Amazon that said it would fit but one of the 4 tabs didn’t align.

I went to O’Reilly and Auto Zone and neither carried the bulb socket.

I went to two different dealers and they wanted to replace the entire tail light wiring harness, but could not find the proper harness in their database.

I then decided to cut off the tab that was misaligned off the Amazon part:





Problem solved.

 

Saw this post after doing some google searching. I am currently having the same problem that you described above on a 2018 Elantra. What exact socket did you purchase off amazon. I’ve asked around and I was told I’d probably need to change the whole socket and harness with the whole taillight since i can’t seem to find the socket harness on his own.

Any help would be really appreciated.