Tail light stays on when the headlights are on!

[FLYBOY]

I have one small little pesky issue with one of my tail lights.
When the headlights are on my left driver side rear amber tail light only, stays lit (steady) not flashing.
Anyone have any Idea what would cause this?
I did replace the dash but even disconnecting the printed circuit still yields the same results.

[Jonathan]

If your right side works okay, perhaps take both lenses off and compare the plastic dividers in the lenses. It might be the middle bulb shining all the way over to the turn signal area if the inside plastic got damaged somehow.

[FLYBOY]

Nope , did that the actual light is steady on the left amber, even tried a different bulb, all new LED bulbs installed!

[Jonathan]

If you swap boards from left to right, does the problem stay where it was or travel with the board to the other side of the car?

EDIT: do a complete swap too, meaning if the problem travels with the board, put the board that wasn't a problem in the spot where the problem was and just confirm that board still works fine in either location.

[FLYBOY]

I'll try that tomorrow and get back to you
But I suspect the board is not the problem it's going to be a wire issue and where to find the problem,
That's not going to be easy!

[DeLorean03]

Check to make sure you don't have 1156 bulbs where 1157 bulbs need to be. Ask me how I know (/)_-)....

[jmettee]

Probably a ground issue. The original tail light board (assuming you have the original) are known to be flakey. Doing the suggested board swap will help to tell if it's the board or if it's in the harness wiring. The connectors at the right, front corner of the engine compartment can corrode too. Unplugging them & plugging them back in can fix some of these issues. LEDs need very little voltage to illuminate & are also sometimes sensitive to low voltages/currents whereas normal bulbs ignore the low electrical potentials.

[DMC5180]

Have you Converted ALL 4 corners of the car too LED Turn singles? If so, did you install an Electronic Flasher (for LEDs)?

[FLYBOY]

Did the board swap same result only on left side amber stays on.
I have the led flasher unit as all lights are LEDs.
I've traced the wire to find out its a green/red to the light at the board if that helps?
But still don't know why it stays lit when the headlights are on?
Tried unplugging and plugging the connector at the right front of the engine compt.
And I have Grady's new boards.
This problem started when I changed the printed circuit on the dash however with it disconnected it still stays
Lit?
It is 1156 bulb I believe and was fine for 6 months since the led conversion.

[DMC5180]

If you have a test light or Multi-meter, do a check at the Black Bulkhead connector. Disconnect it and see if the mating Male pin for the Green/Red wire has voltage with park lights on. It shouldn't, but if it does you know the issue is inside the car.

[FLYBOY]

Okay completely frustrated checked the black plug male mating pin and like I suspected there is power. (great idea dont know why i didnt think of that). I even changed out the printed circuit to my old one, didn't notice the problem before that but I guess it was there because it is still lit with the headlights or park lights on. The green/red wire goes to the amber rear tail light, could it be the ground to that light thats the problem because the right side works fine. And if so, where is the ground to it? Also I have Houstons' new headlight unit, :confused0:could that be the cause of the problem and I never noticed it before, installed last year.
I noticed on that unit the green/red is hooked up to the red/peach and then goes into a solid red wire into the unit!
Not sure if that has anything to do with it or not.:confused0:

Thanks again for any input looking for a needle in a haystack...

[Bitsyncmaster]

Did you say the problem showed up when you redid your dash lights? If so, than my guess would be your dash light connectors got shorted together.

[Ron]

What happens when you turn the left signal on?

With everything hooked up, signals off, and the head/park lights on, does the left turn indicator in the dash come on too? (I'm thinking you may have the wrong bulb or short in the left FRONT socket.)

[FLYBOY]

I put the old printed circuit back in, same result so it's not the dash. I think I just noticed it after I did the job.
As for the lights basically everything is normal except the rear driver amber turn signal will stay lit when the headlights are on or the park lights are on---it however stills flashes like it is supposed to, when the left turn signal is on with the headlights on or off-normal-basically it's just it should not be lit up when the lights are on! The problem is in the rear driver amber, bulb 1156 led with led flasher unit installed.
Oh also in the dash the left turn indicator does not come on with the lights are on it basically works normal.
It comes on when it's supposed to-lights on or off-when it's turned
I'm at a lost?...
Any ideas?

[Dangermouse]

Do you mean the printed circuit at the dash or the one at the tail lamps?

edit : I'm a little confused:

you say that the left rear indicator stays on steady (not flashing) when your headlights are on. Is this independent of whether you have the indicator stalk on the steering wheel in the "left turn' position? What is the left front light doing at this point?

Does the left rear indicator work correctly (flashes) when your headlights are OFF (post 14 is a little contradictory in this case)?

[Bitsyncmaster]

I put the old printed circuit back in, same result so it's not the dash. I think I just noticed it after I did the job.
As for the lights basically everything is normal except the rear driver amber turn signal will stay lit when the headlights are on or the park lights are on---it however stills flashes like it is supposed to, when the left turn signal is on with the headlights on or off-normal-basically it's just it should not be lit up when the lights are on! The problem is in the rear driver amber, bulb 1156 led with led flasher unit installed.
Oh also in the dash the left turn indicator does not come on with the lights are on it basically works normal.
It comes on when it's supposed to-lights on or off-when it's turned
I'm at a lost?...
Any ideas?

Did you look in the connectors on the dash. If one of those copper runs broke off and got stuck in the connectors, that would cause problems.

[Ron]

Oh also in the dash the left turn indicator does not come on with the lights are on it basically works normal.
Now that is odd. The left indicator bulb, left rear turn signal bulb, and one side of the left front turn signal's bulb are all fed with the Green/Red wire, so if one is on, the other two should be on too....

Just for kicks, I'd try a regular bulb there (assuming the left front is acting normal in every way).

[FLYBOY]

Okay, not frustrated anymore...
After testing the rear bulkhead black plug and reinstalling the old printed circuit for the dash... Yesterday
The rear driver amber light still stays lit however Dangermouse and Ron's post got me thinking what was that front left turn signal doing
With the headlights on. Sooooo It too was steady not flashing when it was supposed to be flashing (left turn signal on)
So I took the light out of the front bumper it started blinking then I went to the back of car and the amber light was off with the Headlights ON...YEAH
Problem solved thanks to All, especially Dangermouse, Ron and Dave.


I guess all the bouncing up and down on the flatbed for my move to North Carolina caused the bulb to losen causing the rear to stay on!
Such an easy fix, beats running temporary Ground wires everywhere.

[jawn101]

Okay, not frustrated anymore...
After testing the rear bulkhead black plug and reinstalling the old printed circuit for the dash... Yesterday
The rear driver amber light still stays lit however Dangermouse and Ron's post got me thinking what was that front left turn signal doing
With the headlights on. Sooooo It too was steady not flashing when it was supposed to be flashing (left turn signal on)
So I took the light out of the front bumper it started blinking then I went to the back of car and the amber light was off with the Headlights ON...YEAH
Problem solved thanks to All, especially Dangermouse, Ron and Dave.


I guess all the bouncing up and down on the flatbed for my move to North Carolina caused the bulb to losen causing the rear to stay on!
Such an easy fix, beats running temporary Ground wires everywhere.

Those front sockets for the 1157 bulbs can be kind of a pain. They get rusty and gross and misshapen. I had a very similar problem that also came from an 1157 bulb fitting strangely in a front socket. Clean yours thoroughly and make sure they are gripping the bulbs tight or you'll see this happen again and again :)

Glad you found the issue!