Tail Light Retrofit- AMBER turn signal

One thing I've always hated about my 3 was how they use the Brake light as the turn signal. I'm a big believer in a dedicated color(amber) for turn signal. Unfortunately a lot of manufactures are going away from that in favor for the brake/turn combo. Maybe it's cost savings.IDK, but I am out to change that.

I started looking into just purchasing the European model 3 Tail lights which have an amber turn signal factory(its required by law over seas to have a orange signal). The problem I ran into was the US spec cars are programmed to use the brake AS the turn signal. Which means than even if I got a European lamp, i would still need to find a way to change the computer system to flash a dedicated output for the turn signal.

So I purchased a set of stock tail lights and cut them apart. While inside I painted the chrome black which gave i a much cleaner look. Then I retrofitted a 3" Diode dynamics HD amber LED strip where the OEM reverse was. For the reverse, I retrofitted a 3" white LED strip right next to it(inner). The wiring was a bit tricky as I had to tap off the 3rd brake light for dedicated "BRAKE" then the front camera side markers for a dedicated "TURN" signal. Overall worked pretty well!

In the trunk, pass side there's a harness. Blue wire is 3rd brake light which is where I tapped off.

Running the turn wires through the trunk boot. fun stuff

here's a video showing the functions. They might look dim, but its out in direct sunlight. I assure you they are bright
Also you may notice they are hyperflashing because the car isn't seeing any load(i disconnected the stock brake/turn wire) I left them as is, but if it get annoying I will throw a resistor in there.

Also Decided to do blackout headlight, and AMBER DRL mod

 

[ThunderStrike]

So I'm reading that 2017-2022 USA Model 3s don't need a gateway config change, just the wires with adapters for both the inner and outer. Even if it's all working without the gateway config change, what happens if I do the gateway change on top of the adapters?

Will I have working rear fog lights? And C-style brake lights? Thanks

Looking to use Teslogic's adapter for the outer lights and EVoffer's adapter for the inner lights.

 

[Durzel]

@terranx @E90alex @kodenco

Thanks for all your help with the lights. As suggested, and confirmed by EVOffer, just swapping the ends of the cable around fixed the problem I was having with inverted behaviour. I now have twin reverse & fog lights, and they are very bright which is an unexpected bonus.

 

[E90alex]

So I'm reading that 2017-2022 USA Model 3s don't need a gateway config change, just the wires with adapters for both the inner and outer. Even if it's all working without the gateway config change, what happens if I do the gateway change on top of the adapters?

Will I have working rear fog lights? And C-style brake lights? Thanks

Looking to use Teslogic's adapter for the outer lights and EVoffer's adapter for the inner lights.

If you have the adapters then the outers should work without any configuration change. Some people previously reported issues with the adapters causing bulb out warning and hyper blinking but not sure if they fixed that. Note that with the adapters you lose the first turn signal blink from the tail lights. If you end up getting the configuration change later, it won’t change the function. You can just remove the adapters at that point.

For the inners, the EVoffer adapters won’t work for North American market cars. It will let you physically plug in the new 4 pin inners lights, but it won’t give you controllable rear fogs or function correctly. In fact both rear fogs will come on at the same time as both the reverse lights when the car is in reverse. You will need to modify the harness to eliminate the rear fog wiring or add a wire to connect to the main body harness for the rear fog. If you add the wire you will still need a configuration change to enable the rear fog button on the screen. Otherwise you can hardwire the rear fogs to a physical switch you can control from the drivers seat.

 

[ThunderStrike]

If you have the adapters then the outers should work without any configuration change. Some people previously reported issues with the adapters causing bulb out warning and hyper blinking but not sure if they fixed that. Note that with the adapters you lose the first turn signal blink from the tail lights. If you end up getting the configuration change later, it won’t change the function. You can just remove the adapters at that point.

For the inners, the EVoffer adapters won’t work for North American market cars. It will let you physically plug in the new 4 pin inners lights, but it won’t give you controllable rear fogs or function correctly. In fact both rear fogs will come on at the same time as both the reverse lights when the car is in reverse. You will need to modify the harness to eliminate the rear fog wiring or add a wire to connect to the main body harness for the rear fog. If you add the wire you will still need a configuration change to enable the rear fog button on the screen. Otherwise you can hardwire the rear fogs to a physical switch you can control from the drivers seat.

Appreciate the explanation!

I thought getting the rear fogs working with the config was all that's needed. I don't really see clear steps documented on how to add this extra wire in this thread or anywhere else so maybe I just swap the outters to make it easy...

 

[Durzel]

Why don't NA cars not have rear foglights? Is it just something that isn't required?

If the coding for the rear lights was changed to "Global", would this rear foglight option appear on the UI? is it just completely absent from the UI or always disabled?

Maybe this would need to be changed too....

{
"accessId": 58,
"codeKey": "rearFogLamps",
"content": {
"enums": [
{
"codeKey": "NOT_INSTALLED",
"description": "",
"value": 0
},
{
"codeKey": "INSTALLED",
"description": "",
"value": 1
}
]
},
"description": "Rear fog lamp presence",
"products": [
"Model3",
"ModelY",
"Tamarind",
"Lychee"
]
},

 

[E90alex]

Rear fogs are not required per US regulations. They are allowed, but most manufacturers don’t include them. When cars do include them, they are often misused and people drive around with them on all the time, blinding cars behind them on a clear night.

 

[terranx]

Why don't NA cars not have rear foglights? Is it just something that isn't required?

If the coding for the rear lights was changed to "Global", would this rear foglight option appear on the UI? is it just completely absent from the UI or always disabled?

Maybe this would need to be changed too....

{
"accessId": 58,
"codeKey": "rearFogLamps",
"content": {
"enums": [
{
"codeKey": "NOT_INSTALLED",
"description": "",
"value": 0
},
{
"codeKey": "INSTALLED",
"description": "",
"value": 1
}
]
},
"description": "Rear fog lamp presence",
"products": [
"Model3",
"ModelY",
"Tamarind",
"Lychee"
]
},

Rear fogs aren’t required in the US and Tesla didn’t feel the need to activate them on the 3/Y. The S/X do get them curiously enough. Not sure why they don’t bother on the 3/Y since the wiring is present on those now.

You can enable the rear fog setting as part of the config and then they do work if wired appropriately. I did describe the wiring for the 2021+ models a some time back. Not sure about the 2017-2020 models.

 

[E90alex]

Appreciate the explanation!

I thought getting the rear fogs working with the config was all that's needed. I don't really see clear steps documented on how to add this extra wire in this thread or anywhere else so maybe I just swap the outters to make it easy...

You will get the button on screen with the config change but North American cars are not wired for rear fogs so the button won’t to anything on its own.

I think someone in here did detail how to add the wire but I forgot who. You can also buy the European trunk harness part and swap out the whole harness.

 

[3sr+buyer]

Rear fogs aren’t required in the US and Tesla didn’t feel the need to activate them on the 3/Y. The S/X do get them curiously enough.

Yes, and it seems common to see Model X being driven with the rear fog lamps on when it is not foggy.

 

[terranx]

Yes, and it seems common to see Model X being driven with the rear fog lamps on when it is not foggy.

I firmly believe that’s because for some god forsaken reason Tesla recently made it so that the rear fog lights are a memory setting. So if you turn them on once, they stay on every drive until you manually turn them off. And with teslas interface for lighting controls being the clusterfuck that it is, that’s very easy to do.

 

[Nomisal]

So I'm reading that 2017-2022 USA Model 3s don't need a gateway config change, just the wires with adapters for both the inner and outer. Even if it's all working without the gateway config change, what happens if I do the gateway change on top of the adapters?

Will I have working rear fog lights? And C-style brake lights? Thanks

Looking to use Teslogic's adapter for the outer lights and EVoffer's adapter for the inner lights.

For 2017-2020 cars it's impossible to program global-style lights (different body controllers). So adapters are the only solution available.

 

[Merchant Zhang]

For inner light retrofit. I am a bit of confused about why the EVoffer's adapter connect left and right adapter. Does inner right and inner left harness adapter are different? one with reverse only and other have fog only. So the adapter has to link each other to make two reverse and fog come true?
Or I could simply make two 3pin to 4pin adapter for inner. And after than I will have twin reverse & fog lights? Just as @Adam3 and @terranx done.

​

 

[terranx]

For inner light retrofit. I am a bit of confused about why the EVoffer's adapter connect left and right adapter. Does inner right and inner left harness adapter are different? one with reverse only and other have fog only. So the adapter has to link each other to make two reverse and fog come true?
Or I could simply make two 3pin to 4pin adapter for inner. And after than I will have twin reverse & fog lights? Just as @Adam3 and @terranx done.

​

It's basically a way to get the dual rear fogs and dual reverse lights without having to change any configs or wiring at the car's harness. Not relevant for US cars (since they don't have rear fogs wired up at all for pre-global cars), but should work for the rest of the world.

For newer cars set to "global", they natively have dual reverse and dual rear fog lights.

 

[Merchant Zhang]

Oh I am understand what you mean now. If someone without the "gobal" set they probably would not get dual reverse and fogs light if they use to sperate adapter. So EVoffer's make a adapter to connect both side which can make people have dual reverse and fogs no matter how the car setting is. If someone has "global" setting they could simply make two 3pin to 4pin adapter? Am I correct?

 

[terranx]

If someone has "global" setting they could simply make two 3pin to 4pin adapter? Am I correct?

Well you wouldn't have the physical wire for the 4th wire present, so you'd need to run those to the appropriate pins on the trunk harness

 

[Merchant Zhang]

Considering the complexity of pulling two lines from the 3rd and 8th of the X954F in the trunk to the 4pin adapter. I intend to make a harness that connect the fog lights and reverse lights in the harness on the 3pin respectively into the new 4pin adapter on both sides. Should match the wiring harness EVoffer's made. For North American vehicles, you can simply make a 3pin to 4pin harness, because the #4 fog light in the 4pin will not be used due to the Settings in the gateway config.