Weird turn signal problem

2016 Limited Crewmax. I'm driving today and when I went to switch lanes I got a hyperflash indicating a bad bulb. It worked for daytime running light but the blinker did indeed not work. Pulled the bulb (front, driver's side) and replaced it. I didn't really see a problem with the filament but after putting in a new bulb the everything was fine so I threw out the old bulb.

Everything was good for about 15 minutes of driving. Went to make a turn and same problem. I'm thinking it's more than a bulb problem so I just went home. Pulled the bulb and it looked fine, so I swapped it into the passenger side and it was fine. Put the passenger bulb in the driver's side and it was okay. No problems.

Scratching my head. So far, another half hour of driving and routine turn signal use and all is well. But I'm worried what it might be and every time I use the signal I wonder if it's going to be a problem again.

Any guesses what's going on?

 

Have you checked the rear bulbs? Any LEDs in the turn signal circuit? Ground wires look like they're in good shape? I think 2016 still used a flasher module instead of running the signals of the ECU - that could be part of the problem?

 

Okay I have to elaborate. Yes there is more to the story. Sorry I left this part out. Yes, the rear turn signal / brake light are LED. I forget which model but it's a complete assembly. Only thing is, I've had them on there for at least 5 years trouble free. No effect whatsoever, which is why I didn't mention it at first.

Once upon a time, I tried to put LED bulbs in the front turn signals and naturally I had the hyperflash, so I installed in-line resistors. I kept having problems with the resistors; eventually I took them out and went back to the regular filament turn signal bulbs in the front.

But again, this was years ago. Haven't had any issues in a long time so when it first happened today I immediately figured it was simply that a bulb had gone bad.

While troubleshooting just now (everything is fine at the moment) I tried jiggling the connections near the bulb and couldn't replicate the problem.