Hi guys,

does anyone of you could share with me wiring diagram comparison for tail lights of MY17 and MY21

I would like to attempt to swap them from the newest model into my "old" 2017.

Thanks

 

I doubt if that will work as the shapes are different.

 

It is not the question if they will fit (because they will with the MY21 bumper top part which I already sourced) but if they have same wiring signals as pre-facelift.

 

even if the wires are the same or get the wiring worked out, you will most likely need to do some coding for the lights to work correctly.

 

I’d wager they’re same harness and plug and play. The taillights from 2014-2017 are only partial LED. 2018-2020 went full LED with a slightly tinted housing. Both versions are interchangeable with no issues.

I don’t see JLR changing the wiring harness for something mundane as taillights.

 

the harness may be the same but the lights work differently. On the MY21 and up the turn signal are sequential and the MY18 are regular blinkers, if it’s anything like Audi lights, its all coded.

 

You may be right...or not.
Example: recently I have changed blinkers in my mirrors into sequential and everything works = they work sequentialy.
In the worst case scenario MY21 tail lights will be just blinking as regular blinkers. Everything else should work IMO.

 

Don't have 2021 as I have no need and do not plan to...But here is some wiring info on your model that MAY help.

DC

 

Thanks!
Any chance to share same thing for MY21? For comparison purposes.

 

Did you read my post? It is directly quoted in your post as well. I do not have anything for 2021 as I do not need it. "Don't have 2021 as I have no need and do not plan to"

DC

 

I agree that it is likely to be downstream of the connector. Car is only seeing that it is sending a turn signal. Chip within the sequential blinkers than distributes it each relevant LED in turn. All the aftermarket sequential lights for other manufacturers all work the same so I don’t see why jag would be any different IMO. The number of wires in the connector also would seem to confirm this so I would just do it.Good luck and thanks for being the first !!

 

update:
2021 taillights are now in my possession so that I could make quick test and comparison vs. "old" design.

New harness/plug has 5 wires whereas old only 4. Connectors are the same.
In general I was able to run everything except of sequential blinkers (as expected). So far they work only in standard mode (which is still acceptable) but I suspect there must be a way to overcome this and 2021 model has already built-in sequential module inside the lamp. There must be a "trick" related to signal on 5th wire.
If I would just get in my hands 2021 wiring diagram (same style as already posted by Therock88).

Anybody?

 

its only going to be one of two wires if you think about it
one is neg
one is for brake light
one is for rear light at night
leaving two. You can go to a auto electrician to test it and then cross wire it or DIY using some spare wire and positaps so you can undo it all or try swapping the two left over wire pins in the connector itself or before doing anything use a voltmeter to see which one is active with the indicator on, or stick the new lights on the bench with an external 12v source to each wire in turn. Ultimately do what you are comfortable doing

i guess if anyone with a 2021 can advise if the hazzards are on do the indictors flash as sequential or just as normal blinkers ?may explain the extra wire

 

My exact thought. From analyzing youtube videos I have found out that 2021 hazards work as normal blinkers, no sequential.
Therefore logic says the extra pin has to be for sequential module.
I already identified all pins and signals but when I apply +12V signal on the 5th pin nothing happens. So either slightly higher voltage is required (13-14V range as during normal driving conditions) or the opposite: something like 5V

Will try to test it out and report back.

 

Wait , I wouldn’t apply 14 v through the wiring. More likely to fry something badly. 5v won’t hurt but I think if you were designing the system you wouldn’t make it depend on fluctuating voltage to change how it functions. Maybe the 4th and 5th wire both need to have current to trigger sequential and the 4th only for flashing blinkers
Indicators will work with ignition on and engine off so that’s when not receiving max voltage. It is just a bulb at the end of the day.

 

Good point. I will try this method as well.

 

Mystery solved:

12V just on the 4th connector results in "standard" flashing mode
12V on both 4th and 5th connectors together results in sequential mode

Therefore installing 2021 tail lights you have to choose either standard or sequential mode because bi-mode functionality like on 2021 would require additional 12V wire.
For me this is not a problem.

Connectors on new and old lamps are exactly same but their pins/wiring/signals is slightly different. Again this is not a big deal to fix.

Please keep in mind that all above was veryfied on EU lamps, so I can't comment how/if it will work on US spec cars.

Next stage = installation on the car which will happen in a couple of weeks.

 

If you join 4 and 5 to get sequential, will the hazards also show that way? That might breach vehicle regs ...

 

couple weeks? You can’t post this kind of thing unless you’re ready to get it done and post pictures. You know we only join the forums for the pictures….

 

Yes, you choose either "standard" or "sequential" for both at one time.
Reg. vehicle regs: fortunately in our country control stations are not so keen on checking this...yet. In the end if they will tell me to change into standard now I know it is doable and easy.