2009 Turn Signal issues

I have a 2009 TRD sport that has very strange turn signal issue. When I turn the left turn signal on and the head lights are in the off position, the turn signal flashes and all running lights flash as well. All of them including all lights inside, radio, all running lights. When I turn the right turn signal on the right signal works as it should.
When I turn the head lights on then turn on the left turn signal. The left turn signal arrow on the dash stays lit and also out side the truck front and back left turn lights stay lit. You can still hear it blinking inside but they all stay lit. When you turn the right side turn signal on, the arrow inside the truck lights and flashes but the left side arrow stay solid on. The right side turn signals front and back work and the left side stay solid on.
I have a tow package and read threads on replacing the converter using kit

$150 08921-04960 Towing Wire Harness

08921-04960 so I ordered it. I have checked all bulbs, there all working. I think I found the converter inside the truck on the left upper panel behind fuse box and disconnected it and still nothing still having the same issue.
Has anyone come across this? I made a video below to help you all understand better if it helps.
https://www.youtube.com/watch?v=P3xSfS4n0NE

 

have you replaced any bulbs prior to this issue?
My dad had this happen to his nissan and it was because the prior owner replaced either a dual filament bulb with a single............or a single filament bulb with a double.

 

I have not had to install any new bulbs since I have owned the truck and purchased the truck from a Toyota dealer a little over a year ago. It has 108,000 miles on it.

 

damn.........any recent work at all?
stereo, or other electrical?

 

Nothing, I came out the other morning and there it was. I even tried disconnecting the battery for a dew minutes and nothing.

 

Few minutes

 

I'm gonna guess that it's a bad ground in either the left front turn signal or the left rear turn signal. When the ground is gone, the electricity flows through the running lights to end up at ground.

 

My wife's Sienna mini van did that same thing about a year ago, but I found out I put the wrong bulb in the tail light, but since you haven't had to do anything like that, I would look at 2 other places. It looks like the left turn signal is trying to find a ground and it is back feeding through the system. I would try disconnecting the trailer plug at the back. There is a plug for that on the left rear, under the truck. Check the signal and see it that corrected the problem. There may be corrosion and would cause problems. Pretty simple to check. If that doesn't work, I would disconnect the left rear tail light assembly. You will have to remove the tail light to get to the plug for this. I have had mine out before but I don't remember if there is a separate ground wire there. If there is, it may have broken. I am thinking the problem is in one of the turn signals on the left, and since the front is usually pretty clean and dry, I would look in the back. These are the simple checks. Good luck.

 

Welcome to TacomaWorld, and hope you get it figured out!

 

Welcome to TW

 

This is the way I'm thinking as well.

I think I'd start with completely unplugging the rear tail assembly from the wiring harness and see if things up front start acting normal.

Also, most 2009s have DRL installed. Possible a failure within the flasher under the dash?

I've seen something similar when a dual element light bulb burned out in such a way that the two filaments welded together, but I don't think that's possible on your truck, all the signal bulbs are separate. I think the front uses a dual element bulb, but only one filament is actually wired.

 

Bad ground

 

Hi to everyone that is helping! Thank you for all the input. I found what I think is the connector to the rear trailer light junction and it has a large white coupler holding it together. It looks like a puzzle so I am having little luck with getting it off. I stopped working on it for the night and when I started the truck after I was finished working at my shop which was about an hour, the lights started with the same issue and then after about a minute the issue went away! OK so now i'm at a loss because i do not know what happened to correct the problem but maybe when I was trying to disconnect the rear trailer harness it may have straightened something out (bad ground). I now just have to get the connector off at some point and I do have the entire trailer light kit coming from Toyota today so I may just install it to be safe and it may show me how to un couple the plug in the back.
Thank you all for the help!
I do love my Tacoma and I have two 4runners a 1998 with 396,000 miles on it and a 2000 with over 200,000. I also do all repairs and the light flashing issue on my Tacoma had me shooting in the dark. Thanks again to you all for the help and I will update this thread when I figure it out.

 

I have found my ground issue!!!!
https://youtu.be/7HvO1EuTGt0

 

Glad you solved the problem. A bad ground can cause all kinds of weird issues. Had a box truck once that no matter what blinker you turned on every light on the back of the truck would start flashing.

 

The current goes thru the other bulbs to get to ground thats why the other bulbs light.............

 

Glad you found the issue. Looks like someone added something for a trailer then just abandoned it when they sold the truck. I have learned, whenever there is an electrical issue, look for something that was added or cut. You will most likely find the start of the problem. Not always, but most of the time anyway. Must feel better knowing everything is okay now. Nothing major. Best of luck!