Z3 Roadster amplifier questions

[allexandr]

Hey people! I have a European '98 1.8 roadster with HK amplifier and a CD changer.
The previous owner switched a head unit and since I bought the car the driver's side speakers are not working - footwell and tweeter ones. I believe that the speakers themselves are fine, so I am thinking that the problem is in the wiring (some wires leading to the amplifier are damaged) or the amplifier itself does not work.

Today I was trying to remove the CD changer from the trunk, so I have an access to the amplifier.

What is the best way to test my problem? Does anyone by any chance have a wiring diagram of the amplifier or does anyone know how to bypass the amp (which pins to connect together) so I can test if speakers working from the amp from my head unit? I have pioneer sph-20dab, it should be enough to power those speakers.

AMP is E6845.J E36/7 USA Harman/Kardon

 

[Rudyrov]

Attached is a wiring diagram-color code I acquired some time back. I would check speaker output by using a test speaker or multimeter or even a scope if you know how to use one. Speaker power is in the form of an AC signal so you should be able to read the voltage at the speaker leads if there is power there, you can check a known speaker for a level at a working speaker and then go to a non-working one and see if you have the same power available. Remember to also try with the defective speaker leads disconnected as some shorts could potentially shunt all power to ground. Also, try this technique at the amplifier.
Another test would be to check the wires for continuity to and from the speaker, short the wires together at one end and "ohm" them out for continuity at the other side.

 

[allexandr]

Thank you very much!
I have a multimeter, so I will start by testing if power is going to the speaker, then will test the speaker, and after that will check continuity and amp since it looks a bit more difficult to find the needed wire.

 

[allexandr]

@Rudyrov do you know by any chance how to disconnect the amp? I took down the two on the right easily, but I can't take down the left one. The wire is too short to pull it out and navigate around and clips on the sides do not look to be working as they should. I should just press on them and pull them out, is that right?

 

[Rudyrov]

@Rudyrov do you know by any chance how to disconnect the amp? I took down the two on the right easily, but I can't take down the left one. The wire is too short to pull it out and navigate around and clips on the sides do not look to be working as they should. I should just press on them and pull them out, is that right?

View attachment 244463

I am sorry but I haven't gotten that far myself! Chances are you can loosen the wiring going to it perhaps and gain some clearance?

 

[137699]

I gave up with aftermarket headunits - retro fitted an original BMW one and it sounds soooo much better.