OEM head unit retained even though aftermarket unit fitted

[Collectingbrass]

I've just bought a 2004 3.0. It has a Pioneer head unit fitted, but the OEM unit has been retained and must be on for any sound to be heard. I haven't ripped it all apart, sorry, carefully disassembled it, to trace the wiring and work out what goes where but does anyone know why it would be done this way? If the car sounds familiar, as I can't think there will be many like this, PM me and I will confirm the reg.

 

[Armscarf]

Sounds mad and unnecessary, can you post a couple of pics?

 

[Z4C_er]

I've just bought a 2004 3.0. It has a Pioneer head unit fitted, but the OEM unit has been retained and must be on for any sound to be heard. I haven't ripped it all apart, sorry, carefully disassembled it, to trace the wiring and work out what goes where but does anyone know why it would be done this way? If the car sounds familiar, as I can't think there will be many like this, PM me and I will confirm the reg.

That hurts my head just thinking about it. Yes, some pictures would be good.

 

[Collectingbrass]

OEM head unit in boot. (The bag it is in is supposed to be velcro'ed to the back wall of the boot but the adhesive is failing)

 

[Collectingbrass]

Aftermarket head unit. It uses a Pioneer power lead to connect to what I think is the OEM ISO block, though I can feel another one block deep in the dash. The photos show this lead coming out below the HVAC controls, this is temporary for these pictures as the wiring was very tight but normally it is up behind the head unit as you would expect.

 

[Z4C_er]

Hi, I made this to explain to myself what went on. If you buy the correct harness adapter, this should all work fine. Disregard my amp and substitute your head unit.

 

[Collectingbrass]

Thanks @Z4C_er. Is that for a normal car or what you think has occurred in mine? Sorry if that's a daft question, it's too early

 

[Z4C_er]

Thanks @Z4C_er. Is that for a normal car or what you think has occurred in mine? Sorry if that's a daft question, it's too early

That's the diagram I made for my Z4. I have an E86. 'I think' you should be able to disconnect the looms in your car, buy a new adapter harness and plug and play. I don't see any reason why the head unit is in the trunk. My only caveat here is if you have the full-on sound system, which is digital, and that changes things. That's when I hand over to the pros. Is it a 6 speaker system? Is any sound coming from the door speaker adjacent to the handle?

 

[ph001]

That head unit in the boot is the most bizarre ICE integration I have ever seen!!!!!

 

[dhobbs]

I recently replaced my OEM head unit with an aftermarket one and used an adapter cable. No problem at all.

What's the wiring like behind you HU?

 

[Armscarf]

As I suspected, mad. Using Z4C_er's diagram my advice is strip all the after market rubbish out all the way back to the OEM connector behind the dash. Source a good stereo and install in the normal way. I've done 4 now so happy to help anyway I can.

 

[Collectingbrass]

Thanks Armscarf, that's what I was thinking. The existing head unit is pretty good and up to date so I'm going to aim to keep that and remove the OEM unit from the Network.

 

[Armscarf]

Thanks Armscarf, that's what I was thinking. The existing head unit is pretty good and up to date so I'm going to aim to keep that and remove the OEM unit from the Network

That should work well, the only reason I added and after market unit was to get hands-free phone function.

 

[Collectingbrass]

Any ideas what the White / Red wire would be for? It's spliced into the red wire behind the ISO block but I couldn't trace it once it went behind the glove box, even though I had the glove box out.