superjoe83
Senior Member
In this thread I'm going to show how I swapped 2019 HD 2500-3500 tail lights into a 2018 3500 (2019 1500 LED Tails will NOT fit). I'm not sure how this will work with older BCM's but if someone with an older truck wants to do this go ahead and post in this thread and I will do what I can to help.
I got my lights from ebay, I'm assuming off of a wrecked or flooded truck since the seller cut off the wiring pigtails for me which is a big help, you can buy the repair pigtails from the dealer but they are over $60 per side. Both tail lights use the same connector and are wired identically
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The hardest part of this project was adding the wires for the rear turn signals to the BCM, there is not much room to work and depending on the radio you have you may have to unbolt the amp and move it out the way to get to the BCM. The amplifier is held on by three screws, the farthest one up you have to fully remove, but the two lower ones you just have to loosen, they are a 7mm bolt, it makes more sense once you get your head under there and take a look.
The BCM is located to the left of the steering column up against the firewall, the two connectors you are interested in are the large cam lock connectors in the center of the BCM, labled C5/E and C6/F
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On C5 pin 3 is the output pin for the left rear turn signal
On C6 pin 42 is the output pin for the right rear turn signal
I don't have the proper terminals for the BCM connector so I have a temporary solution until I can source the proper terminals.
I used some 1/8 female spade terminals with the plastic insulation removed.
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I soldered the wire to the terminal, then with the connector still connected to the BCM I inserted the terminal and wire into the backside of the BCM connector then used a 90 degree pick to push the terminal into the BCM pin. Its not ideal, but for now it works. Once I get the correct terminals I will post the part number and where to get them, I'm going to order a few different kinds and hopefully will get the correct ones.
I ran the two turn wires through the grommet in the fire wall that the shifter cable goes through and followed the main harness back to the rear of the truck and up to each tail light.
I then cut off the factory tail light plugs and soldered and used heat shrink to attach the 2019 pigtails, the wire colors do not match so you will have to refer to the connector views to wire it up correctly. You can go to http://connectors.dcctools.com/home.htm and look up your truck and find the tail light connector and pinouts, its a really good resource for stuff like this.
View media item 28372
If you notice there a three wires that are not hooked to anything, those are the CAN IHS wires and power for the blindspot sensor, which will be my next project to see if I can get it to work on these trucks, I have a good feeling that I can get it working.
All taped up
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and installed
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Now to the AlfaOBD BCM setup
In the BCM "Car configuration change" menu go to "CBC I/O Rear Turn Lamps Output Present" Change it to "Yes"
Then go to "CBC Features-Combined Rear Lighting Enable" and select "No"
Then go to "CBC Features-Single Element Tail Lamp" select "Yes"
That is all I did to the BCM and I have no bulb out messages and the brake light drops out on the side that has the turn signal on. The only thing weird with this is that the red brake lights will flash when you lock/unlock the truck with the FOB, and will flash red when the hazards are on, but will flash amber when the regular turn signals are used.
I will get some video later tonight showing them working.
I'm sure I missed something, so reply if you have any questions.
I got my lights from ebay, I'm assuming off of a wrecked or flooded truck since the seller cut off the wiring pigtails for me which is a big help, you can buy the repair pigtails from the dealer but they are over $60 per side. Both tail lights use the same connector and are wired identically
View media item 28370
View media item 28369View media item 28367
The hardest part of this project was adding the wires for the rear turn signals to the BCM, there is not much room to work and depending on the radio you have you may have to unbolt the amp and move it out the way to get to the BCM. The amplifier is held on by three screws, the farthest one up you have to fully remove, but the two lower ones you just have to loosen, they are a 7mm bolt, it makes more sense once you get your head under there and take a look.
The BCM is located to the left of the steering column up against the firewall, the two connectors you are interested in are the large cam lock connectors in the center of the BCM, labled C5/E and C6/F
View media item 28365View media item 28366
On C5 pin 3 is the output pin for the left rear turn signal
On C6 pin 42 is the output pin for the right rear turn signal
I don't have the proper terminals for the BCM connector so I have a temporary solution until I can source the proper terminals.
I used some 1/8 female spade terminals with the plastic insulation removed.
View media item 28376
I soldered the wire to the terminal, then with the connector still connected to the BCM I inserted the terminal and wire into the backside of the BCM connector then used a 90 degree pick to push the terminal into the BCM pin. Its not ideal, but for now it works. Once I get the correct terminals I will post the part number and where to get them, I'm going to order a few different kinds and hopefully will get the correct ones.
I ran the two turn wires through the grommet in the fire wall that the shifter cable goes through and followed the main harness back to the rear of the truck and up to each tail light.
I then cut off the factory tail light plugs and soldered and used heat shrink to attach the 2019 pigtails, the wire colors do not match so you will have to refer to the connector views to wire it up correctly. You can go to http://connectors.dcctools.com/home.htm and look up your truck and find the tail light connector and pinouts, its a really good resource for stuff like this.
View media item 28372
If you notice there a three wires that are not hooked to anything, those are the CAN IHS wires and power for the blindspot sensor, which will be my next project to see if I can get it to work on these trucks, I have a good feeling that I can get it working.
All taped up
View media item 28373
and installed
View media item 28374View media item 28375
Now to the AlfaOBD BCM setup
In the BCM "Car configuration change" menu go to "CBC I/O Rear Turn Lamps Output Present" Change it to "Yes"
Then go to "CBC Features-Combined Rear Lighting Enable" and select "No"
Then go to "CBC Features-Single Element Tail Lamp" select "Yes"
That is all I did to the BCM and I have no bulb out messages and the brake light drops out on the side that has the turn signal on. The only thing weird with this is that the red brake lights will flash when you lock/unlock the truck with the FOB, and will flash red when the hazards are on, but will flash amber when the regular turn signals are used.
I will get some video later tonight showing them working.
I'm sure I missed something, so reply if you have any questions.
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