Yet another LED tail light thread.....

[Samsonlabs]

3 questions - my truck came with LED tail lights from the factory

1: Why is it so friggin hard to find good smoked lens LED tail lights for vehicles that CAME with LED tail lights? Everything it seems is w/o led tailights version

2: Why am I getting signal/tail light out errors with Recon LED tail lights when my truck came with LED tails from the factory? I replaced the incandescent reverse light with an LED but I dont get reverse light errors only signal/tail

3 Why do I have to add resistors to LED lights WHEN MY TRUCK CAME WITH LED LIGHTS FROM FACTORY? Im sorry but I look at things with a degree of common sense. It appears to me that if you buy a truck with LED tailights obviously it has resistors built in. SO having said that, one would think that if you bought a set of LED tail lights for a truck that came with LED tail lights, those also would have BUILT IN RESISTORS!! Otherwise why would there be a difference between LED tails for trucks w/o and with LED tails?

 

[NJMOPAR]

Headlights & taillights always specify if they're for original LED applications. Most are to convert from halogens and have built-in resistors/decoders to accomplish this. Others are direct swaps LED to LED and don't need the resistors.
Do the Recons say "for original equipment LED vehicle"? If not they're the problem.

 

[Samsonlabs]

Do the Recons say "for original equipment LED vehicle"? If not they're the problem.

yea they were but came with incandescent reverse lights.....I replaced those with LEDs and after a month or so they started giving me "left turn signal out" or "left tail light out", but no reverse light out errors. Also my left signal indicator hyperflashes in the cab but works fine outside. Am I wrong to assume that all lights go through a decoder or resistor pack? Perhaps I had a decoder or resistor pack go bad in the left tail light.

 

[stimpy433]

Check to see if your third brake light is out.... it gives you the "left tail light out" message also if the third brake light is out.

 

[NJMOPAR]

If your truck had built-in LED reverse bulbs and the Recons had halogens you need resistors for the LED reverse bulbs.
Sounds like you have conversion taillights to me.

 

[Samsonlabs]

If your truck had built-in LED reverse bulbs and the Recons had halogens you need resistors for the LED reverse bulbs.
Sounds like you have conversion taillights to me.

Actually I think this is common across the board for reverse lights in general to use incandescent reverse bulbs. Correct me if I am wrong, but now that I think about it, doesnt the harness for the reverse light retain the actual bulb with a twist lock, whereas the LEDs up top for signal/brake/running just has a connector to a board of lights in the housing? I think that might be what has got me screwed up. I was thinking the whole assembly had lights included. At work now, will pull the lights and check when I get home.

Check to see if your third brake light is out.... it gives you the "left tail light out" message also if the third brake light is out.

good to know, i wasnt aware of that.

 

[stimpy433]

Both the LED and Halogen tail lights use standard bulbs for the reverse light. T20 for the LED or 921 for the halogen tail lights. They both are standard twist bulb holders, just different bulbs, the T20 is physically a little bigger bulb then the 921.

 

[Graygoose]

Retroshop.us if you want OEM smoked LEDs...

 

[shadowhawk]

my Spyder lights do the same thing. Got a replacement set and still had the issue, even though they swore there was a resistor built in.

 

[superjoe83]

If your truck came with LED tail lights there is a fault sense wire that is used to tell the BCM that the lights are working properly, the aftermarket tail lights don't use that wire so the BCM thinks there is a problem with the lights, you can disable the fault sense function with alfaobd

 

[shadowhawk]

If your truck came with LED tail lights there is a fault sense wire that is used to tell the BCM that the lights are working properly, the aftermarket tail lights don't use that wire so the BCM thinks there is a problem with the lights, you can disable the fault sense function with alfaobd

it disables the fault sensor for all faults then, not just the blinker function, from what I understand.

 

[Samsonlabs]

so the alphaobd kills the hyperflashing and all?

 

[jjones1642]

I called Recon today and they said they are working on a version for the factory led replacement. They said check back in 4-6 weeks.

 

[shadowhawk]

so the alphaobd kills the hyperflashing and all?

I guess I should try it and find out

 

[lpennock]

so the alphaobd kills the hyperflashing and all?

You can disable all rear lightning DTC with AlfaOBD so yes.

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[OnSale]

3 questions - my truck came with LED tail lights from the factory

1: Why is it so friggin hard to find good smoked lens LED tail lights for vehicles that CAME with LED tail lights? Everything it seems is w/o led tailights version

2: Why am I getting signal/tail light out errors with Recon LED tail lights when my truck came with LED tails from the factory? I replaced the incandescent reverse light with an LED but I dont get reverse light errors only signal/tail

3 Why do I have to add resistors to LED lights WHEN MY TRUCK CAME WITH LED LIGHTS FROM FACTORY? Im sorry but I look at things with a degree of common sense. It appears to me that if you buy a truck with LED tailights obviously it has resistors built in. SO having said that, one would think that if you bought a set of LED tail lights for a truck that came with LED tail lights, those also would have BUILT IN RESISTORS!! Otherwise why would there be a difference between LED tails for trucks w/o and with LED tails?

Because the Recon lights are $600 pieces of junk. Also, the voltage from the recon lights differs from your stock lights so your truck is reading the different voltage and thinks you taillights have LED’s that have burnt out.


Sent from my iPhone using Tapatalk

 

[Samsonlabs]

Because the Recon lights are $600 pieces of junk. Also, the voltage from the recon lights differs from your stock lights so your truck is reading the different voltage and thinks you taillights have LED’s that have burnt out.


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Yea IM not a big fan of them myself anymore. It looks like most all of them are plagued with lil glitches though. Seems a shame a person has to check voltage use to determine resistor values or completely disable with alphaODB to use the same style lighting that came on your truck to begin with.

One more question about alphaODB if anyone knows. Im running a tune on my truck that I have to revert to stock everytime I go to dealer cause they always seem to need to flash my computer. Is alphaODB the same? if you go to dealer with an alphaODB tune do you have to go back to stock to keep from bricking your computer? I dont really know if it would brick or not either with a tune or AlphaODB but IM sure ya'll know as well as I do if the dealer flashed your comp and bricked it, there would be a "well its because you are running a tune/AlphaODB" excuse forthcoming just before a new comp install.

 

[shadowhawk]

Yea IM not a big fan of them myself anymore. It looks like most all of them are plagued with lil glitches though. Seems a shame a person has to check voltage use to determine resistor values or completely disable with alphaODB to use the same style lighting that came on your truck to begin with.

One more question about alphaODB if anyone knows. Im running a tune on my truck that I have to revert to stock everytime I go to dealer cause they always seem to need to flash my computer. Is alphaODB the same? if you go to dealer with an alphaODB tune do you have to go back to stock to keep from bricking your computer? I dont really know if it would brick or not either with a tune or AlphaODB but IM sure ya'll know as well as I do if the dealer flashed your comp and bricked it, there would be a "well its because you are running a tune/AlphaODB" excuse forthcoming just before a new comp install.

if they reflash your pcm, bcm, or ecm, then you'd have to reapply your changes. they revert to what is known for your VIN and the alfa changes are not "known"

 

[Jimmy07]

Because the Recon lights are $600 pieces of junk. Also, the voltage from the recon lights differs from your stock lights so your truck is reading the different voltage and thinks you taillights have LED’s that have burnt out.


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Lights don’t present voltage, or different voltages to the truck. Voltage is supplied to the lights through the BCM, so when the truck is running, the tail lights are supplied with 14.x volts, and the lights use all of the voltage supplied to them, regardless of what type of lights are being used. It’s the resistance that the LEDs present to the BCM that it determines if it thinks a bulb is out. That, and combined with the fact that the BCM is supplying PWM power to tail light circuits factory equipped with halogens, which causes LEDs to potentially flicker when installed without disabling the PWM, or installing “decoders” or resistors.
@Samsonlabs, the reason that aftermarket LED tails aren’t usually offered for factory equipped LEDs is exactly what @superjoe83 said- the factory equipped LED trucks have a fault sense wire on each side that is monitoring minor resistance changes in case only one or two of the LED chips burns out on the array of LEDs in the factory tails. This wire can’t be used on aftermarket LEDs, unless they come up with a box that will present exactly what that wire is looking for. The easiest way to take care of this is to disable those fault sense wires with AlfaOBD. The lights will still be monitored if an assembly burns out, and there’s an open circuit detected. There is a DIFFERENT setting in AlfaOBD that completely disabled the rear lighting DTCs. You don’t disable that setting, because then you won’t be alerted at all if any rear facing light is actually out.

 

[shadowhawk]

Lights don’t present voltage, or different voltages to the truck. Voltage is supplied to the lights through the BCM, so when the truck is running, the tail lights are supplied with 14.x volts, and the lights use all of the voltage supplied to them, regardless of what type of lights are being used. It’s the resistance that the LEDs present to the BCM that it determines if it thinks a bulb is out. That, and combined with the fact that the BCM is supplying PWM power to tail light circuits factory equipped with halogens, which causes LEDs to potentially flicker when installed without disabling the PWM, or installing “decoders” or resistors.
@Samsonlabs, the reason that aftermarket LED tails aren’t usually offered for factory equipped LEDs is exactly what @superjoe83 said- the factory equipped LED trucks have a fault sense wire on each side that is monitoring minor resistance changes in case only one or two of the LED chips burns out on the array of LEDs in the factory tails. This wire can’t be used on aftermarket LEDs, unless they come up with a box that will present exactly what that wire is looking for. The easiest way to take care of this is to disable those fault sense wires with AlfaOBD. The lights will still be monitored if an assembly burns out, and there’s an open circuit detected. There is a DIFFERENT setting in AlfaOBD that completely disabled the rear lighting DTCs. You don’t disable that setting, because then you won’t be alerted at all if any rear facing light is actually out.

so what setting specifically do I need to change?