I recently bought an Audi A4 1.8T (Semi-Auto) B5 and instantly changed the tape player for a stereo.

I just did a basic unplug, insert harness adapter, plug in. No cut wires. the only loose wire is the telephone mute wire.

The back speakers don't work.

Any ideas?

Also, I want to get to the speakers in the front without snapping the covers, any ideas how to do this? Should I take the whole door panel off?

Thanks in advance.

 

The back speakers are powered by an amplifier. One of the adapter connectors behind the head unit should use RCA cables to plug into the head unit's rear-channel output to provide a signal to the rear speaker amplifier.

 

Thanks for the reply, I had a feel about in the cavity but can't find any RCA wires, the old tape player didn't have any ports on the back.

Should there be an amp already in the car? If so, any idea where?

 

The RCA cables would be provided by an adapter that attaches to the stock wiring. When I got my head unit from Crutchfield they included the adapter.

The stock amp is attached to one of the rear speakers, on the driver side I believe. Should be visible by looking at the speaker from the trunk.

 

I'll have a look tomorrow for that.

Whilst feeling around behind the head unit I found another wire, it had a fluffy covering on the wire and a small brown plug for a socket on the end.

Any ideas on what that could be?

 

If it's the one I'm thinking of, that would be for the radio antenna. There should be another adapter cable for that.

 

Nah it's not the radio antenna, it's another one, a much smaller wire.

The plug on the end is brown plastic and square, it looks like it should go into a part of the harness which might not be there, but it was definitely not able to go into the old tape player either. I will upload photos tomorrow to see if that helps.

 

Ohhh that one, I had forgotten about it. My guess is that should be for grounding or something, in any case it is useless so it should be tucked away.

 

Ok thanks, I tuck that wire away.

I have had a look at the underneath of the rear speakers and one in encased in metal, so I assume this is the one with the amp?

I can't see any space for an RCA cable on either speaker though?