Ok so I have searched and searched but found nothing on this. My drivers side rear turn signal is blinking fine one minute but super fast the next. I replaced the bulb and the issue is still there. Anyway, while I had the whole tail light out I was checking all wires to see if I could figure out why it's doing that and I notice I had a smaller wire coming from underneath the top tail light bulb. So I got the bright idea to pull it out. it looks like some kind of sensor and I had a heck of a time getting it back in and still it's only half way in. Anyway, did I mess anything up by pulling that out? I should mention that it's a 1996 Deville. Turn signal problem is annoying, all of the other lights works fine so I'm assuming is a loose wire somewhere. So is that a sensor or what? Thank you!

 

Not sure what's up with what you did. Turn lights and hazards on then look and see what light is out. Look at that socket, there should be a 12v constant brown wire, black is ground a colored wire with a blinking 12v. check terminals within socket.

 

Yea I'm sorry I kind of didn't explain enough. The fast blinking turn signal I assume is a messed up wire somewhere. What I was wondering was when I took my tail light out, I notice a small wire underneath the first light. I pulled it out and it appears to be some sort of sensor looking thing. Do you know what that is for? And thank you for the info on looking into my fast blinking turn signal!

 

Maybe if you take a picture of it. There is no sensor at the tail lamp.

 

https://i.imgur.com/LOwKQE1.jpg

Please let me know if I uploaded that right! Thanks!