General Any electronic or auto electric guys here?

[Never_Rolled]

I wired in an LED light strip to the 12v dome light circuit. It works great or so I thought. Turns on when the hatch is opened shuts off when hatch is closed.
as expected.

The OEM cargo light is an LED module. I noticed while driving tonight the lightbar remained on while the OEM led was off even though they are on the same circuit. My working theory is something in the OEM module shuts it off while the circuit still remains hot. I tapped off the circuit right before it goes into the module. I’m thinking I need to meter out the module circuit to figure out what shuts it off and resolder my led strip to there. Does this sound about right?

One other odd thing I noticed. The OEM light shuts off about 10 seconds before the LED strip. At first I thought it might be a cap in cig. plug I wired into the tape strip but now I think that’s false. First world problems when the cargo area isn’t bright enough. The LED strip works awesome BTW. I attached it to the bottom of the retractable shade.

I had to remove the rear cargo panel to wire in the cig lighter outlet. It came out great but it would be nice if the lightbar wasn’t on while driving. I have pics I can post them if anyone is interested. The entire drivers side rear had to be removed as well as the back seats. It was a fun project.

 

[sparkuri]

Checked the fuse did you?
Amperage matters it does.
Hunting for ground electricity does;
Horny it makes me.

 

[Never_Rolled]

Checked the fuse did you?
Amperage matters it does.
Hunting for ground electricity does;
Horny it makes me.

That isn't my problem. The circuit works so power and ground are there. It shouldn't be on when the hatch is closed as it's wired to the dome light circuit. Dome light is off, led tape strip is on. Both on same circuit.

 

[Rambo John J]

lol the electrician speaking like yoda

 

[sparkuri]

That isn't my problem. The circuit works so power and ground are there. It shouldn't be on when the hatch is closed as it's wired to the dome light circuit. Dome light is off, led tape strip is on. Both on same circuit.

That's because the dome light amptitude works on FM.

 

[Never_Rolled]

lol the electrician speaking like yoda

Electricians aren't always good with electronics. Very different field.

 

[sparkuri]

Electricians aren't always good with electronics. Very different field.

You're talking about the same ball of wax.
It's a car.
Your hood switch is in line with your dome light, did you check the wiring thoroughly on the dome light connections? It's HIGHLY likely there are additional accessory wires in the led bar harness not utilized but possibly impactful, and it's likely you've got different draw on the light bar than the dome light which affects the relay, and possibly the fuse.
You'll have to get a wiring diagram for that year/make/model & that specific circuit.
If the amperage deviates at 12v, then your electricity will backfeed through the relay and use ground for the neutral and stay on.

That's just one (likely) possibility.
Wiring diagram is crucial, as it will show you the circuit order and everything on that circuits relay.
It's not just about hooking up a 12v load to a 12v line.

 

[sparkuri]

I'd say yes, take pictures.

 

[Never_Rolled]

You're talking about the same ball of wax.
It's a car.
Your hood switch is in line with your dome light, did you check the wiring thoroughly on the dome light connections? It's HIGHLY likely there are additional accessory wires in the led bar harness not utilized but possibly impactful, and it's likely you've got different draw on the light bar than the dome light which affects the relay, and possibly the fuse.
You'll have to get a wiring diagram for that year/make/model & that specific circuit.
If the amperage deviates at 12v, then your electricity will backfeed through the relay and use ground for the neutral and stay on.

That's just one (likely) possibility.
Wiring diagram is crucial, as it will show you the circuit order and everything on that circuits relay.
It's not just about hooking up a 12v load to a 12v line.

I soldered the wires myself the the led tape. They come in a roll. There are no wires attached. Just a + - trace that gets soldered to. If the circuit backfed through the relay I suspect the OEM light would stay on also. I can understand something in circuit detecting a draw and the ECM regulating that but as stated both lights are on that wire so something has to be on the OEM led module telling it not to turn on. I'm going to meter the circuit with the hatch closed. I think other possibility is the OEM module expects 12 volts to operate. Possibly with the latch closed there could less current but enough for the led tape as that has no regulation circuit. I will figure it out with a meter eventually but I wanted to know if someone knew for sure. I will try to hunt down a schematic.

 

[Never_Rolled]

Solved but not fixed yet. I started thinking of even the smallest things even if they didn’t makes sense, what makes both lights different. There was a negative groundblock to the body. Instead of tapping into the negative wire on the OEM circuit I tied into the groundblock.

I backprobed the OEM module. Engine on hatch closed 0 volts. I then used the same positive but backprobed the groundblock. Engine running closed hatch boom 14v. I don’t really understand how the other negative is keeping the lightbar energized but it is. I now have to take the back of the vehicle apart again and tie my negative into module negative. It was a learning lesson for sure.

 

[Never_Rolled]

 

[Rambo John J]

@sparkuri is in another country FYI
looks like a lil project for sure
he was round like 20 minutes ago

 

[Never_Rolled]

@sparkuri is in another country FYI
looks like a lil project for sure
he was round like 20 minutes ago

It's all done. I had to take it apart again today. If you see the grounding lug on the body panel that is where I had my original ground. In the first pic towards the back left you see the OEM light harness hanging. I tapped my + from there and grounded it to the body. I didn't know that the - was the switched leg of the circuit. I assumed it was + and I was wrong. I removed the - from the grounding lug. Cut the - wire off the OEM harness tapped and soldered in the cig. outlet - wire and it works with the cargo light on and off when the hatch is open or closed. Now I know next time before I wire in something that is switched I will make sure which leg is switched before proceeding. Basically my mistake was 90 minutes of labor and two broken clips. I originally broke 4 clips and bought six. Lucky today I had the two extra. That chrome piece going across where the hatch latch is has 6 clips holding it down. That is where I broke 1 today and one on the side panel. First time I broke 4 off that piece. We do it nice cause we do it twice!

 

[Rambo John J]

It's all done. I had to take it apart again today. If you see the grounding lug on the body panel that is where I had my original ground. In the first pic towards the back left you see the OEM light harness hanging. I tapped my + from there and grounded it to the body. I didn't know that the - was the switched leg of the circuit. I assumed it was + and I was wrong. I removed the - from the grounding lug. Cut the - wire off the OEM harness tapped and soldered in the cig. outlet - wire and it works with the cargo light on and off when the hatch is open or closed. Now I know next time before I wire in something that is switched I will make sure which leg is switched before proceeding. Basically my mistake was 90 minutes of labor and two broken clips. I originally broke 4 clips and bought six. Lucky today I had the two extra. That chrome piece going across where the hatch latch is has 6 clips holding it down. That is where I broke 1 today and one on the side panel. First time I broke 4 off that piece. We do it nice cause we do it twice!

right when you become an expert at something you won't have to do it for another 20 years
that is the golden rule it seems

 

[Hauler]

Holy fucking Jesus.

Bro...

 

[Never_Rolled]

This guy went even further. I didn't do the pin contacts. I was worried over time the would lose contact and create more problems so I opted for the cig plug. This is the video where I got the idea from. Mine is new model so a couple things weren't the same but in general it was close. The second time I only had to remove the rear passenger seat back. The first time I removed both.

I enjoy fixing things and or making things work better. I am also not afraid to pay someone for something I can't do or don't have the proper equipment.