BMW z3 wiring in the trunk

[Nehemy]

I just purchased a bmw z3 and the break lights and rear lights were not working so I opened the trunk and saw this brown extension connected to those oem bmw wires. I thought the brown extension was the reason why the lights did not want to turn on so I pulled it out from the oem bmw wire. After doing so my car is refusing to power any where, and I am not able to start it.

The location is at the passenger side on the trunk.

What is supposed to be connected to those wires?

 

[ExMX5owner]

Hi there, I fixed up you duplicate post for you, .

But what you have there looks like someone has been into the car with a machete, And well past my understanding of wiring. Maybe someone here can offer some advice. Welcome anyway...

 

[Duncodin]

I just purchased a bmw z3 and the break lights and rear lights were not working so I opened the trunk and saw this brown extension connected to those oem bmw wires. I thought the brown extension was the reason why the lights did not want to turn on so I pulled it out from the oem bmw wire. After doing so my car is refusing to power any where, and I am not able to start it.

The location is at the passenger side on the trunk.

What is supposed to be connected to those wires?

I'm not sure anyone will be able to give a reliable answer based solely off the pictures. There's so many wires that have been chopped and twisted together it's impossible to say what goes where. Wires left bare. I wouldn't even connect a battery to that bird's nest.

If it was me I'd chop off the whole mess and solder/crimp in a rear loom section from a scrap car

 

[colb]

Looks like all the brown wires are lives taped into battery and connected to the main loom wires to provide power for some reason. This would have bypassed the fuse box connections that should have provided power to circuits like your rear lights. Why it's not starting could be ignition fuses blown seems to me it's a complete bodge job gone wrong.

 

[IanA]

Yes that is a real mess and potentially dangerous. The two big cables from the battery have fuses under the black clip-on covers. The starter cable is fused at 300A. The cable to the fuse box (which handles the ignition and everything else) looks to have been bypassed by the brown add-ins. It is fused at 200A. Those brown wires can't carry all of that. There is a busbar under the fuse box by the dashboard that carries a total of 480A fused circuits. Obviously they don't all pull that sort of amps in normal use but we're talking big power here.

Rather than guessing which wires to pull, it really needs someone who knows these cars to check out the electrics starting with those big fuses from the battery. Then the fuse box needs a good check to try and work out why it's been bypassed.

Make sure that you can disconnect the battery quickly if anything goes wrong and keep a fire extinguisher handy!!!

 

[Nodzed]

Yeh that's had an ID.10.T conversion. Don't put a battery on it.

 

[Nehemy]

Yes I removed the battery so after all that it’s probably best to do what you guys told me

 

[Rudyrov]

Many of the wires that are twisted pairs of similar colors are audio system wires going to the various speakers and coming in from the radio to the cars amplifier that has been removed. There should also be a constant power and a switched power to the audio components as well as a triger with from the head unit to turn the amplifier on. There are color charts for those wires that should make it easy for you to ID the various wires.

 

[Duncodin]

Many of the wires that are twisted pairs of similar colors are audio system wires going to the various speakers and coming in from the radio to the cars amplifier that has been removed. There should also be a constant power and a switched power to the audio components as well as a triger with from the head unit to turn the amplifier on. There are color charts for those wires that should make it easy for you to ID the various wires.

That kinda explains some of it. Maybe my suggestion of chopping it "all" out was a bit overkill But still needs somebody who knows what he/she is doing to sort it all out before powering it up.

 

[Rudyrov]

Perhaps this stereo wiring detail will help?