'87 Speaker Wiring & Amplifier help

[Howaboutdat]

I'm trying to replace the original radio in my car ('87 325E). The replacement stereo I'm installing doesn't have a built-in amplifier, so I was planning to either install an external amp or if the car already has an amp, see if I can use that. I've identified the original radio as a KE-81ZBM-02, and it has the in-dash fader knob. From what I can tell, the car may have the premium sound system it has the front kick panel speakers, and I believe it also has the wiring for tweeters, although I could be mistaken.
I've been trying to locate the amplifier. I checked the trunk and couldn't find one.

Does anyone know if there's a wiring diagram specifically for cars with the in-dash fader knob, or can anyone confirm whether these cars actually have a separate amplifier and where it's located?

[Howaboutdat]

Update: I found out that I was wrong about the car having the premium sound option. So there is no factory amplifier.

With that, I'm still trying to figure out the wiring for the factory radio with the in-dash fader knob. If anyone has a wiring diagram for that setup, I'd appreciate the help.

[82eye]

the etm has a number of wiring diagrams for different sound systems and radios. i'd look it up there.

[amarino]

This post has all the different options and wiring diagrams:

https://www.r3vlimited.com/board/forum/e30-technical-forums/car-audio-electronics/387356-understanding-e30-speaker-and-amp-wiring

What I did and would suggest is to just run all new speaker wires and leave the original wiring alone. Where are you planning on putting the amp?