Backfeeding Turn Signals

[ima93chevyguy]

Hey guys,

so this isn't a new problem, I just thought it had went away but now it has come back.

The problem: My turn signals backfeed to each other. i.e. when I turn on my right turn signal the left turn signal also dimly flashes with the right one and vice versa. The reason I noticed it was doing it again is that now my ashtray bulb will slightly light up with either turn signal.
I have all exterior and interior LED's so that doesn't help because they're all real finnicky. However it never did this after I installed the LED's it just randomly came about. I realize the LED's don't take a lot of voltage to dimly light up so I feel like it's some ground somewhere.

What I've done:
Previously I cleaned and redid the rear ground at the trailer harness.
I replaced the ground strap body to frame
I cleaned the common ground in the harness that runs along the core support on the pass side
I replugged all the sockets
I checked to make sure all grounds I know of were secure.

Other Notes:
I have a light up hitch that lights up with the brake, it will light up with ONLY the right turn signal. It only has ties to ground and brake, it does not connect to parking lights or turn.
I need to replace the block to body ground strap but I'm not sure where it connects on the block if anyone could help there.
With the truck running it is much worse than if it is off, I'm assuming because there's more voltage in the system.


So, anyone have any ideas or anything I could try? It just randomly started doing it again yesterday evening when previously it was not noticeable. The only thing I did was literally touch one of the ground straps, that's why I went to them first.

 

[someotherguy]

The engine ground strap is part of a pair of straps - one attaches to the rear of the passenger side head, and goes to the firewall stud near the heater core hoses. Another strap goes from that same stud to the passenger side frame rail.

Definitely suggest making sure all grounds are good before chasing any other possible causes, as grounds usually account for the bulk of weird lighting issues.

Converting to LED's can sometimes be a baffling experience as the quality of offerings varies greatly. I've seen all kinds of weird **** happen with LED swaps and still experience slight issues on my '06 SS with full exterior LED conversion, but I've learned to live with it. Experimenting with different products has reduced those issues quite a bit and the truck behaves about 95% normally at this point.

Also don't overlook the possibility that one or more of your devices has gone bad, especially if they used to behave one way and that behavior has since changed on its own. On my wife's old Magnum SRT8 I eventually gave up on switchback LED's in the turn signals because they kept burning up, literally. The same LED's worked in my 300 SRT8 which is the same electrical system...

Richard

 

[ima93chevyguy]

Yea my next step is to definitely replace the other ground strap it just got dark on me yesterday before I got to it and it's raining today and tomorrow.

I'm also probably going to check all of my sockets just to double check they are all clean and making good contact.

Then from there I'll just be guessing haha.

 

[ima93chevyguy]

Alright I went out for a little while today inspecting stuff

I checked/cleaned:
Trailer Harness ground - still good
Driver side core support ground - good
Passenger side fender ground - good
Rear harness needs to be cleaned, it was kind of gunky.

Nothing changed after all this

The only thing I was able to find out was, if I unplugged the rear harness, my ash tray light would dimly light up if the key was even on and then also blink with turn signals. I never cranked the truck but I couldn't really see any back feed in the front with it off.
Also with the right turn signal only, the tag lights and my hitch light both light up.

So, is my problem in the rear or does that even mean anything?
Also can someone tell me more grounds that I could check and clean.

If I can't find my problem then I'm probably going to slap some diodes on there and leave it alone.