Rear blinker doesn't work with headlights on after tail lamp replacement.

My rear driver blinker does not work when my headlights are on after replacing a broken tail lamp. The bulb works because the blinker works when the headlights are off, and blinks when I lock the truck. Also, when the headlights are on only half of the rear tail light comes on.

 

Aftermarket tails?

 

Stock tails. Well, the replacement was from eBay. But it's just the shell right? Like the wiring and bulbs are still OEM.

 

I would double check your wiring to make sure something was not damaged, or possibly not plugged in properly. If indeed you just replaced the housing only it should have no effect. What damaged the old housing? Possibly a wire was damaged or pulled somewhere as well. Check your grounds too

 

My impatient ass backing into a wall lol. I've tried multiple bulbs and really plugged em in tight, don't even know where to begin with checking the wiring though... Not a big electrical guy.

 

Some have some internal LED strips and other fuckery. But if it was just the shell then obviously, nvm me haha.

Do the tail lights just blink once then stop blinking?

 

Make sure you have the correct bulbs.
If the other side is working, compare bulbs or swap bulbs to see it issue moves.

 

The blinker works properly when I don't have my headlights on

 

Yeah I was thinking of doing that, was hoping to avoid taking the other side off in case I'm the one that messed up the wiring taking off the first one lol.

 

Are you sure the bulbs are in the correct sockets? Sounds like an issue that might arise when you throw in an LED bulb with the incorrect resistance in place.

 

When your headlights are on, do the tail lights blink once and stop blinking? Or never blink at all.

 

That's a good question I've never actually looked. I'm assuming never blink at all cause the front blinks rapidly like the tail is out. Also, the driver mirror turn signal stays on when the headlights are on, I'm assuming that's an indicator the truck thinks one of the other blinkers is out?

 

Yeah, the wiring harness is a different fit for each bulb harness and none of the actual bulbs were removed from their harness.

 

Gotcha, such a weird issue. Has to be some sort of wiring issue, maybe a wire is loose on one of the harnesses?

Good luck in finding the gremlin.

 

That's my concern and I'm not confident with electrical at all... Doesn't sound cheap to bring to a shop either.

 

The bulbs are still the same in the headlights/ taillights? Not led?

 

Correct, tried the bulbs that came with the replacement lamp (two sets because the first lamp didn't fit properly) and the OEM bulb.

 

Sounds like there's no connection to your 3rd wire (white with black line).

When headlights are off, current can flow (in wrong direction, but it's a bulb so doesn't necessarily matter), but when headlights are on, it can't follow the correct path to ground once you turn your blinker on, which results in no change. That also explains why your side mirror lights stay illuminated.

 

I'm not great with electrical, suggested troubleshooting/resolution for this? Also huge thanks if you nailed it lol

 

Likely the bulb just isn't making contact with that connection. May have bent it in the socket when swapping out the housing, and now the connection is non-existent or weak. You can try to pop the bulb out and see what the contacts look like, and bend any that may be not making good enough contact.

If you have a multimeter that can check continuity, then you can try this:

With the bulb installed, you should get a path to ground (bare metal of the chassis would be best ground connection) between any of the 3 wires going to the bulb socket. I'm not able to check with my truck right now, but the first thing I mentioned will be the easiest and likely culprit.