The trunk broken wire issue- 3 black wires in harness- which is which?

[Dudeman]

Sorry to repost but I am a little desperate here. I am suffering the same issue that everyone else is regarding the tech service bulletin TSB #20-BE-007H I have tried fix mine and there are 3 black wires that were all severed and they are the same color- all black and they are all cut. So, I am not sure what to connect these to, meaning 3 black wires need to go to 3 black wires. How do I know which ones to are the correct matches? Why these are not different colors I will never know. Anyone have any idea what to do here? And after all of this, it did not fix the problem and now i have no brake lights when I press my brakes. running lights work, no brakes. Nothing else is working (Camera, back up light etc). its like I made it worse. So very pissed at Hyundai, this should be a recall not a TSB. For your amusement, here is what I found when I pulled away my conduit. Any help is greatly appreciated! Absolutely amazing Hyundai....

 

[5.0KDM]

You might have to do it by trial and error to figure those out. Ill try to help after i get out of work but try to find a diagram of the wires.

 

[Dudeman]

You might have to do it by trial and error to figure those out. Ill try to help after i get out of work but try to find a diagram of the wires.

Thank you Andy- I will certainly try all 3 and report back....

 

[DaleNet]

If they are all black, they may all be ground wires. Usually power wires are colored. One may go to each break light and the last to your camera.

 

[gksuelzle]

Sorry to repost but I am a little desperate here. I am suffering the same issue that everyone else is regarding the tech service bulletin TSB #20-BE-007H I have tried fix mine and there are 3 black wires that were all severed and they are the same color- all black and they are all cut. So, I am not sure what to connect these to, meaning 3 black wires need to go to 3 black wires. How do I know which ones to are the correct matches? Why these are not different colors I will never know. Anyone have any idea what to do here? And after all of this, it did not fix the problem and now i have no brake lights when I press my brakes. running lights work, no brakes. Nothing else is working (Camera, back up light etc). its like I made it worse. So very pissed at Hyundai, this should be a recall not a TSB. For your amusement, here is what I found when I pulled away my conduit. Any help is greatly appreciated! Absolutely amazing Hyundai....

Just repaired this myself last month. It is alot easier than you think. Its looks like a big mess but you need to get more wire to make everything longer. Then you get a kit from Amazon Wirefy 50 solder & Seal butt connectors. You may need two boxes of these if you have never used them before. You use them with a heat gun to make a permanent water proof wire connection. As you use the heat gun you are looking to see just a little change in the solder that tells you it melted, try not to overheat them. When in doubt underheat them. You could also use a black plastic wire cover called wire loom this will prevent the chaffing in the future. You will need thicker than you think to cover everything at the end, like 3/4 inch or 1 inch bigger will be better hard to fit everything back into the loom because of the multiple connections. Most of the connections you should be able to match up using the colors of the wire. It looks like you are missing big gaps of wire. The small red ones you can see which ones looks like you can tell which are connected. You could also guess with the red and then test your signal lights, tail lights. The large thick wire has two wire in it that have shielding wrapped around it and it carries the video for the backup camera. I just wrapped some metal tape around it that you can buy at home depot or lowes in the venting section. I think it works even without the sheilding the shielding will improve the video quaility. Its important to buy some 16 gauge or better size is 18 gauge 12 volt wire so you can make everything longer. You will put the solder connectors on each end and you will need the small connectors so that why you might need two boxes. These connectors heat shrink the connection and solder the connection all with just a heat gun. These connectors are easier than any other wire connection. Makes a very thin flat secure permament connection. You can also thread some black heat shrink 1/4 inch or bigger dual wall shrink tubing it the best one shrinks and glues at the same time. You place this on a part of the wire that will not get hot and then slide over after your first heat shink the first connection. You have to thread it up on the wire when no heat will get then slide it down. Your goal will to make everything about 8 inches longer and everything the same length so you can put is all back into the loom after you are done. If they wont fit they just put them into two seperate looms. You want as much of the wire harness as possible covered with the loom. You secure the loom with black electrical tape at the end of the project and then open an close the trunk and see how it will rub and maybe change the zip tie anchors to help the rub in the future. If you repair it this way you might never have to repair it again, otherwise if will fall apart again very quickly. These solder connectors work amazingly well and are very easy to use. You should practice a few times on scrap wire with the bigger connectors on bigger wires. You overlapt the two wires in the sleeve and then heat unti you see the solder get just a little shiney. You might be able to match the black wires based on the cut frey pattern or the length. If not then get some little alligator clips and and test connect them then test your tail signal and other lights them and see how they control the tail lights or the trunk lock actuator. If you don't ground them out to the body it wont blow a fuse.

 

[Dudeman]

Just repaired this myself last month. It is alot easier than you think. Its looks like a big mess but you need to get more wire to make everything longer. Then you get a kit from Amazon Wirefy 50 solder & Seal butt connectors. You may need two boxes of these if you have never used them before. You use them with a heat gun to make a permanent water proof wire connection. As you use the heat gun you are looking to see just a little change in the solder that tells you it melted, try not to overheat them. When in doubt underheat them. You could also use a black plastic wire cover called wire loom this will prevent the chaffing in the future. You will need thicker than you think to cover everything at the end, like 3/4 inch or 1 inch bigger will be better hard to fit everything back into the loom because of the multiple connections. Most of the connections you should be able to match up using the colors of the wire. It looks like you are missing big gaps of wire. The small red ones you can see which ones looks like you can tell which are connected. You could also guess with the red and then test your signal lights, tail lights. The large thick wire has two wire in it that have shielding wrapped around it and it carries the video for the backup camera. I just wrapped some metal tape around it that you can buy at home depot or lowes in the venting section. I think it works even without the sheilding the shielding will improve the video quaility. Its important to buy some 16 gauge or better size is 18 gauge 12 volt wire so you can make everything longer. You will put the solder connectors on each end and you will need the small connectors so that why you might need two boxes. These connectors heat shrink the connection and solder the connection all with just a heat gun. These connectors are easier than any other wire connection. Makes a very thin flat secure permament connection. You can also thread some black heat shrink 1/4 inch or bigger dual wall shrink tubing it the best one shrinks and glues at the same time. You place this on a part of the wire that will not get hot and then slide over after your first heat shink the first connection. You have to thread it up on the wire when no heat will get then slide it down. Your goal will to make everything about 8 inches longer and everything the same length so you can put is all back into the loom after you are done. If they wont fit they just put them into two seperate looms. You want as much of the wire harness as possible covered with the loom. You secure the loom with black electrical tape at the end of the project and then open an close the trunk and see how it will rub and maybe change the zip tie anchors to help the rub in the future. If you repair it this way you might never have to repair it again, otherwise if will fall apart again very quickly. These solder connectors work amazingly well and are very easy to use. You should practice a few times on scrap wire with the bigger connectors on bigger wires. You overlapt the two wires in the sleeve and then heat unti you see the solder get just a little shiney. You might be able to match the black wires based on the cut frey pattern or the length. If not then get some little alligator clips and and test connect them then test your tail signal and other lights them and see how they control the tail lights or the trunk lock actuator. If you don't ground them out to the body it wont blow a fuse.

Thx for this, this is exactly what I used actually. Standard butt connectors are laughable and came right off and yep, I used longer 18 gauge I had to make everything longer. Great info about the shielded wire for the camera, that wire was super jacked up so I will dig into that tonight to see if I can find the fray in the camera and fix that as well. Thx again for your help, so awesome that this community exists. If you are ever in denver, I owe you a beer!

 

[dan77062]

This was very helpful to me as I did the same repair. I used regular solder connections covered with heat shrink just because I do enough electronics that I'm used to that. I couldn't figure out which ends of some of the red and some of the black wires to connect. It was reassuring to hear that I could just do a test connection and see what works without worrying about blowing a fuse.

I verified that all three solid black wires connect to ground on the car side (not on the lamp/sensor side where they are returning from). Also, I discovered two identical yellow wires where one powers the right turn signal lamp (amber) and the other the right reverse gear lamp (white). Those lamps are co-located on the trunk. If you get them swapped, your turn signal will be white instead of amber. I don't know of any way to distinguish them other than trial and error.

There is also a third yellow wire and two identical brown wires with a black stripe. I don't know where those go, as they were among the few wires that had not fully broken, so I didn't have to guess at how they connected.

Side note: I was leaving my trunk open while doing this repair out of concern that I would lose the ability to actuate the trunk lever. However, I learned you can open the trunk with the physical key on your fob. Look for the keyhole under the middle ridge of the trunk.

Also, leaving the trunk open draws about 3 amps out of the battery, even with the trunk lamp off. Beware of draining your battery if you want to leave the trunk open for an extended time. I disconnected the battery and used a power supply for testing the connections instead.

This repair took me about 4 hours to do. It definitely should have been a recall especially considering that there was a mix of broken power and ground wires. The fact that it wasn't is likely sufficient to send me back to Lexus rather than another Genesis.