Aftermarket third brake light

[Royal50]

Has anyone been able to successfully install an aftermarket third brake light on a 2nd gen RAM without any issues? There's a lot of discussion on the net ut nothing solid on how to do it. Mine is a smoke led type and the problem is the cargo lights always stay on even with the truck off and switch off. I guess the problem is that leds dont take much power to come on and thats why they stay on all the times. Some people say to gat resistors, some people say to cross wires. But just not enough info on how to do it with instructions.

 

[Big Red Truck]

Not sure what your talking about, my 99 has a third brake lite above the rear window? I have also installed a smoked Rams head on the tailgate that works with running lights and stop light. Just need to wire it to the correct wire.

 

[Royal50]

Not sure what your talking about, my 99 has a third brake lite above the rear window? I have also installed a smoked Rams head on the tailgate that works with running lights and stop light. Just need to wire it to the correct wire.

When you comnect the harness from the new third brake light to the truck's harness, the cargo white lights stay one. They never turn off.

 

[corneileous]

If you’ve got an aftermarket third brake light that has both the LED cargo lights, you’ll need to splice a resistor jumper to the hot and the ground of the cargo light circuit.

I had the same problem on my 3rd Gen.

https://www.ramforum.com/threads/ca...anzo-led-3rd-brake-light.106537/#post-1549321


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[DodgeTx]

I got mine from amazon and did not have any problems on my 96 v10 or my 01 cummins. they were direct plug in and fit correctly. Then again both are tow trucks and i have rear led lights to see at night when loading.

 

[Big Red Truck]

If your talking about the third brake light/cargo lights above the rear window all I did was replace the stock lights with plug in led lights and everything works fine. My cargo lights work as stock and can be turned off with the dash switch dimmer. There is so many types of lights out there being manufactured in countries with little to no QC. I find about 10% of the aftermarket dash leds simply did not work or failed within a short time.

 

[Royal50]

If your talking about the third brake light/cargo lights above the rear window all I did was replace the stock lights with plug in led lights and everything works fine. My cargo lights work as stock and can be turned off with the dash switch dimmer. There is so many types of lights out there being manufactured in countries with little to no QC. I find about 10% of the aftermarket dash leds simply did not work or failed within a short time.

I know the bulbs can be replaced with leds but i wanted a smoke colored housing as well. Plus the stock one was leaking and cracked.

 

[Royal50]

Can someone help with this issue? I finally got around buying a 10w 100ohm resistor like someone suggested and the leds for the cargo never turn off. Is it the wrong resistor or wired wrong? My new harness has a black, white, green, and red. The white is power and the black i thought it was the cargo

 

[Royal50]

I even tried cutting what i thought was the cargo wires and just not have them, since all i really need from getting pull over is brake lights, but without the cargo wires uncut the brake light section does not work. This is how i tried it with the resistor.

 

[corneileous]

I even tried cutting what i thought was the cargo wires and just not have them, since all i really need from getting pull over is brake lights, but without the cargo wires uncut the brake light section does not work. This is how i tried it with the resistor.

View attachment 171287

OK, can you not trace those wires to see which two wires go to your brake light and which two wires go to your cargo light?

What you need to do first and foremost is not cut any of the wires that’s on the harness that goes to your third brake light. All you’re going to be doing with that resistor is taking one black wire of it and splicing it inline to one of the wires that goes to your cargo light, and then take the other black wire that’s attached to it and splice it inline to the other wire that goes to your cargo light. Don’t mess with the two wires that goes to your brake light as that’s probably the reason why your third brake light doesn’t work right now.

Yeah, you don’t need your cargo lights to be DOT compliant but if you hook them up the right way with that resistor, you’ll be able to have all your lights work the they were intended and not have that annoying glow of your cargo lights.


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[Royal50]

OK, can you not trace those wires to see which two wires go to your brake light and which two wires go to your cargo light?

What you need to do first and foremost is not cut any of the wires that’s on the harness that goes to your third brake light. All you’re going to be doing with that resistor is taking one black wire of it and splicing it inline to one of the wires that goes to your cargo light, and then take the other black wire that’s attached to it and splice it inline to the other wire that goes to your cargo light. Don’t mess with the two wires that goes to your brake light as that’s probably the reason why your third brake light doesn’t work right now.

Yeah, you don’t need your cargo lights to be DOT compliant but if you hook them up the right way with that resistor, you’ll be able to have all your lights work the they were intended and not have that annoying glow of your cargo lights.


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So i read that one wire from resistor goes to power of cargo lights and the other wire goes to negative of cargo lights. I did just that and nothing. I tested the resistor amd it is good. The led harness has a white wire which i believe is the power. The other wire that I believe is negative for cargo is the black. I figured it out by tracing the wires from the stock one. But like I said nothing.

 

[DodgeTx]

Have you tested the new led 3rd brake light with just 12v power? make sure they work correctly?

Have you checked to make sure your cargo light switch next to headlights is turned off?

I've overlooked minor things like this before as the previous lights had been burned out, so couldnt ever tell it was on lol!

 

[corneileous]

So i read that one wire from resistor goes to power of cargo lights and the other wire goes to negative of cargo lights. I did just that and nothing. I tested the resistor amd it is good. The led harness has a white wire which i believe is the power. The other wire that I believe is negative for cargo is the black. I figured it out by tracing the wires from the stock one. But like I said nothing.

Are you sure you were using the right two wires? Either way, as long as you never cut any of your wires, it should work. Did you verify that your new third brake light did work before?

Hooking one of these resistors up to control that glow, really is no different from using a resistor to control the hyperflash on your turn signals after upgrading from incandescent to LED bulbs.

Also, did you get your resistor from that guy at autoillumination.com? If so, did you email him first to tell him what you have and what you’re trying to do, to make sure that you get the right resistor? I’m not sure if they’re all the same or not but, when I last had to fool with finding the right resistor, it was on my old 2008 and, I have no idea what the resistor was on the new third brake light that I put on my 2018 because I spent the extra money and bought an aftermarket LED third brake light that already had the resister wired in so I had to do was just unplug the old one and plug in the new one.


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[corneileous]

So i read that one wire from resistor goes to power of cargo lights and the other wire goes to negative of cargo lights. I did just that and nothing. I tested the resistor amd it is good. The led harness has a white wire which i believe is the power. The other wire that I believe is negative for cargo is the black. I figured it out by tracing the wires from the stock one. But like I said nothing.

Are you sure you were using the right two wires? Either way, as long as you never cut any of your wires, it should work. Did you verify that your new third brake light did work before?

Hooking one of these resistors up to control that glow, really is no different from using a resistor to control the hyperflash on your turn signals after upgrading from incandescent to LED bulbs.

Also, did you get your resistor from that guy at autoillumination.com? If so, did you email him first to tell him what you have and what you’re trying to do, to make sure that you get the right resistor? I’m not sure if they’re all the same or not but, when I last had to fool with finding the right resistor, it was on my old 2008 and, I have no idea what the resistor was on the new third brake light that I put on my 2018 because I spent the extra money and bought an aftermarket LED third brake light that already had the resister wired in so I had to do was just unplug the old one and plug in the new one.


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[Royal50]

Are you sure you were using the right two wires? Either way, as long as you never cut any of your wires, it should work. Did you verify that your new third brake light did work before?

Hooking one of these resistors up to control that glow, really is no different from using a resistor to control the hyperflash on your turn signals after upgrading from incandescent to LED bulbs.

Also, did you get your resistor from that guy at autoillumination.com? If so, did you email him first to tell him what you have and what you’re trying to do, to make sure that you get the right resistor? I’m not sure if they’re all the same or not but, when I last had to fool with finding the right resistor, it was on my old 2008 and, I have no idea what the resistor was on the new third brake light that I put on my 2018 because I spent the extra money and bought an aftermarket LED third brake light that already had the resister wired in so I had to do was just unplug the old one and plug in the new one.


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So i did buy the resistor from them but I just went for the 10w 100ohm as suggested. I also emailed customer service to ask them if i bought the correct resistor but they're not responding me. I haven't tested the led third brake light because I'm not sure what each wire is. I don't trust matching it with my stock one because maybe it's wired for another truck make. Who knows. Almost feel like buying another one. I just wish I knew which one works. I simply just want a black smoke lens with leds.

 

[corneileous]

So i did buy the resistor from them but I just went for the 10w 100ohm as suggested. I also emailed customer service to ask them if i bought the correct resistor but they're not responding me. I haven't tested the led third brake light because I'm not sure what each wire is. I don't trust matching it with my stock one because maybe it's wired for another truck make. Who knows. Almost feel like buying another one. I just wish I knew which one works. I simply just want a black smoke lens with leds.

Which third brake light you get? Shouldn’t be too difficult to figure out which wire goes where. If it’s too difficult on the new one, use your original light to trace the wires down, then correspond that when the new light is plugged into the harness on the truck.

Try snapping a good picture of the backside of the old light and the truck plug in.


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[Royal50]

Which third brake light you get? Shouldn’t be too difficult to figure out which wire goes where. If it’s too difficult on the new one, use your original light to trace the wires down, then correspond that when the new light is plugged into the harness on the truck.

I will take some pics tomorrow. Thanks

Try snapping a good picture of the backside of the old light and the truck plug in.


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Which third brake light you get? Shouldn’t be too difficult to figure out which wire goes where. If it’s too difficult on the new one, use your original light to trace the wires down, then correspond that when the new light is plugged into the harness on the truck.

Try snapping a good picture of the backside of the old light and the truck plug in.


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I will take some pictures tomorrow. Thanks for taking the time to help me out. It's kind of frustrating cause every day that i can't figure it out I have to put the old one back and make sure it's seal well cause it rains here lol.

 

[Moparfanatic21]

These guys are wrong here (no offense). These trucks get supplied ground and the brake switch applies the power (basically backwards on how everyone else does it). So the ship these lights out as just how everyone else does it (remember our trucks are backwards). What you have to do if its led is wire a jumper wire and cut the printed circuit board with a razor knife.

 

[corneileous]

These guys are wrong here (no offense). These trucks get supplied ground and the brake switch applies the power (basically backwards on how everyone else does it). So the ship these lights out as just how everyone else does it (remember our trucks are backwards). What you have to do if its led is wire a jumper wire and cut the printed circuit board with a razor knife.

I didn’t have to do that on my 08. Also didn’t have to do it on my 18, either. I took the two wires that run to the cargo light circuit on the new third brake light assembly and wired in a resistor the same exact way you’d wire one in to a tail light or a front signal light for when replacing incandescent bulbs for LED bulbs to correct the hyperflash. It’s not rocket science. The power and ground for the cargo lights shouldn’t have anything to do with the brake light circuit as that’s all in it’s own. They just share the same light fixture.

I don’t think you actually follow what’s going on here and without pictures, I’m not even so sure what the OP’s doing/not doing to get the same desired results.


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[Moparfanatic21]

I didn’t have to do that on my 08. Also didn’t have to do it on my 18, either. I took the two wires that run to the cargo light circuit on the new third brake light assembly and wired in a resistor the same exact way you’d wire one in to a tail light or a front signal light for when replacing incandescent bulbs for LED bulbs to correct the hyperflash. It’s not rocket science. The power and ground for the cargo lights shouldn’t have anything to do with the brake light circuit as that’s all in it’s own. They just share the same light fixture.

I don’t think you actually follow what’s going on here and without pictures, I’m not even so sure what the OP’s doing/not doing to get the same desired results.


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Because in in 02 Ram switched everything to normal. You don't understand here and I'll try to explain better man. Ground is also switched for the lights and the cargo/brake switch supply power. In 2002 (1500) and 2003 (2500/3500) this reversed. So the aftermarket companies wire everything in this way. So now the cargo/brake lights are sharing a common ground, and power source, when in fact they should be separate.

The four-pin harness on the truck has two circuits, one for the brake lamps which is on a switched POSITIVE (+), and one for the cargo lamps which is on a switched GROUND (-). The circuit on the replacement lamp in this review is not designed correctly and uses a common ground for both circuits. Put that together and what you get is a brake lamp that works correctly but cargo lamps that stay on all the time, even when the key is turned off. On the factory harness the two pink wires run the cargo lamps and the other two wires run the brake lamps.