Full tail light on SE

[giorgitus]

I installed it today. Unfortunately, the connector for the tow hook in my car (SE 2023) is different. It has a bus connector with a black negative connector, a red positive connector always powered, and also a white-blue one always powered. All the other thinner cables are for the bus and have voltages of 3v. For now, I've connected it to the license plate light, but I would like to find a way to make it turn on exactly like the tail lights. Any ideas?

 

[DANC]

Any pictures of the hitch connector? Particularly any sowing the colours if the wires going in from the harness and the dummy plug connector? Having a look at the wiring manual the hitch connector is definitely the easiest way. The next would be splicing the wiring to the left or right taillight. But this needlessly more complicated than finding the right pin out on the hitch connector.

 

[giorgitus]

Here's the connector for the 2023 model. I measured the voltages: the black wire is negative, while the thick white and blue wires next to the thick red wire are both at 12 volts, but they seem to be always powered, or at least not controlled by the headlights switch. Meanwhile, various connectors in the middle are all at either 3 volts or 0 volts relative to the negative black wire.

 

[DANC]

Here's the connector for the 2023 model. I measured the voltages: the black wire is negative, while the thick white and blue wires next to the thick red wire are both at 12 volts, but they seem to be always powered, or at least not controlled by the headlights switch. Meanwhile, various connectors in the middle are all at either 3 volts or 0 volts relative to the negative black wire.

this is very confusing... So there is no dummy connector that is closing the circuit from the BCM to the rear left tail light (see grey wire on the snip of the wiring diagram)? Mine is also a 2023 model and has the same connector as seen in Joehn's post. You are sure this is the connector attached to the middle of the rear left wheel well and not the connector lower in the boot space?

 

[giorgitus]

Yes, it's the only connector above the left wheel near the hook for manually releasing the charging socket. Mine is the model with the rear windshield wiper purchased in November 2023 in Italy. From what I read in the tow hook installation thread, the kit used is indeed no longer compatible with the new models.

 

[DANC]

Yes, it's the only connector above the left wheel near the hook for manually releasing the charging socket. Mine is the model with the rear windshield wiper purchased in November 2023 in Italy. From what I read in the tow hook installation thread, the kit used is indeed no longer compatible with the new models.

Ok great. I'm not sure about local specifics or the trailer hitch conversation but looks like the jumper cable on the dummy connector is still there and is just in white. This is the cable which would complete the circuit between the BCM and the rear left tail light? you could probably test this by removing the dummy connector and turning the headlights on. Would expect the right to turn on and the left to not. If this is the case (keep in mind I'm not an auto electrician) I would try tapping into the white cable for the through tail light positive and would try connecting the through tail light negative to black (not sure which insert you would need to work with the factory connector) .

 

[giorgitus]

It was the first thing I tried, but that cable compared to the ground has a fixed voltage of 3 volts and does not vary when turning the headlights on or off. I disassembled the rear headlight and found the cable that supplies power, but I don't want to cut the car's wires, so for now, I connected it to the license plate light. Then, if someone encounters the same problem as mine and finds a solution, I will try to replicate it. thank you so much

 

[dimosa]

I was looking to buy and install one too. Thanks for the detailed descriptions everyone.

 

[Vingnut]

I do hope no one is using the cars cables ditectly to the towhook contact, the system is suposed to be connected via a towhook module whit separate power suply so the car is separated from the trailers electrics.

The reason I stil warn about this is a friend of me who had a not so lucky encounter whit falling trailer electrics, where a simple fault in the trailers electrics damaged his Volvo XC60.
The body controll module was destroyed and that was well north of 1000£ to change, on a MG..... God knows the cost for the boddycontroll module so be careful.

 

[giorgitus]

Ok great. I'm not sure about local specifics or the trailer hitch conversation but looks like the jumper cable on the dummy connector is still there and is just in white. This is the cable which would complete the circuit between the BCM and the rear left tail light? you could probably test this by removing the dummy connector and turning the headlights on. Would expect the right to turn on and the left to not. If this is the case (keep in mind I'm not an auto electrician) I would try tapping into the white cable for the through tail light positive and would try connecting the through tail light negative to black (not sure which insert you would need to work with the factory connector) .View attachment 25063

I forgot to mention that if I remove the female connector and thus disconnect the bypass cable, the rear light continues to function correctly. Therefore, I would say that its purpose on that connector is no longer relevant.