Hey all,

I was hoping someone could help me understand the sound system wiring a little better. I have a 95 90 Sport with the base CC radio and the amplified rear door speakers. My question is if there is an easy way to disconnect the power/remote to the amped rears. I suspect the amps may share its power source and remote switch with the power antenna, so I may need to rip off the back doors to get to it. Anyone have any advice/experience?

Here's the story:
I replaced the factory radio with a nice Kenwood head unit (with an all red display to match interior!)and I installed some 6x9 speakers in the rear deck. I have the wiring harness with the supplemental input for the amped rears door speakers by using the rear outs on the Kenwood. I thought I was good to go...but now I need some help!

The amped rears never sounded great and "popped" when first turned on but I thought they would sound better with a Ground Loop Isolator and the line outs from the Kenwood. Wrong; still pop and were getting more interference from the engine (whining as engine revved). The sound level was also much lower than that from the rears and the upgraded from dash speakers, so I decided to cut the amped rears out. After some experimenting, I discovered the remote wire coupled to the antenna input also turns on the amps. So even when they are getting no signal, they still click on with a pop and hum with the engine. Sooo when I couldn't take the hum anymore I installed a switch on the inside of the center console that I only switch on when I want to listen to some FM. And that's where I'm at right now. I am about ready to take the rear door(s) apart to deal with it (not sure if an amp is on both sides?). Just hoping there is a simpler workaround. Any help would be great!

Thanks for looking!

 

ive read it 3 times still dont get it what you want.

 

So basically, you added speakers to the rear deck right? And you left the wiring going to the rear door speakers?

The simplest thing you can do is just pull the rear door panels and unplug or remove the rear door speakers.

 

Do it. There should be two small amps on each back side of rear speakers so just simply unplug the wires from both speakers, and forget about it. It's not too complicated to pull out the door panels. Check youtube there might be an explanation of how to do this. It's the best way to solve your issue.

 

You need to remove the door panels to unplug the door speakers.
There's an amp on each speaker.
I just had mine apart to remove the amplified speakers in preparation for regular speaker install.

 

"I installed some 6x9 speakers in the rear deck."

I have been trying to figure out the best way to do this...how did you do it? The metal deck frame is a real headache to deal with.

 

Hey guys, thanks for the info.

I will prob make this my weekend project, and I can post some pics of everything once I get the doors off. I guess my only question now is whether disconnecting the amps will affect the power and lead to the antenna, but I guess I will figure that out soon enough. Does anyone know if the amps share power with the head unit or antenna? I would like to replace and hook up the rear components at some point, just trying to figure out the best way-prob just get a modest amp to run the 6x9s.

So GuyllFyre, you removed your amps/speakers and replaced with new speakers wired straight to your head unit? Did you just splice into the rears wire harness and hard-wire into new speakers, or did you have to run all new wires?

93_Audi_90CS- As for the 6x9s in the deck...it was def harder and messier than I anticipated. I'm glad they are in...but I cant say that I would highly recommend doing unless you are ready for a long battle! But what I did is this:
-Carefully measure the deck and use a sharpie to outline holes using guide to trace after poking holes in the center (you may want to slightly angle them to line up at least two of the mounting holes, as the metal cage has holes in it)
-Use a utility knife to cut away the carpet and try to remove as much of the layer of insulation below it as possible
-Now the crazy part; laying in the trunk, I used my sawzall with a short metal cutting blade to cut through the metal...def wear glasses here! Follow your guide as close as you can. Then I used a Multi-tool and metal cutters to clean up the cut. Shop-vac all the debris out of your trunk, there will be lots!
-I applied Dynamat to the bottom of the deck, which I would recommend as the deck is not an optimal barrier, and if you wrap some around the hole with the adhesive exposed it will help set and hold your speakers in place.
-Use small bolts (I forget what size) and lock nuts to tightly fasten speakers
-Then just run some speaker wire from your head unit (or use a 2ch amp)and you are good to go!

The whole job took around 4 hrs, so not too bad, but the metal deck is not fun or easy!

 

Unplugging the speakers with the amps won't affect anything else.
The two pairs from the head unit go to the doors along with other power, etc. These then all plug into the speakers with the amps. You just tap off of those two wires.

What I did is hack the plugs off the amp/speakers and wired them to just use the two pins from the head unit, added a little wire to go to the new speakers, and that allows me to plug back into the stock wiring without molesting the stock harness.

 

Ok, that seems easy enough. Are you using an aftermarket head unit? When I was still using the amped rears I was had a separate harness that plugged into my head units RCA rear outs and then had the female end connector for the rear speaker harness. So I was not sure if that harness was just sending an unfiltered signal to the speaker amps, but it sounds like they can be used to power the replacement speakers as well, correct?

Also, I was just checking out my factory unit and noticed that it has inputs for both front and rear antennas but I only see one antenna plug. Was the front antenna an optional feature? There is also a small pin in the middle that appears to be for a ground, which I found the connector for-its a brown wire with a copper coupling. Would it be wise to splice my head units ground into this? I'm thinking it would help with the intermittent engine noise interference.

Thanks!

 

Yea, I'm going to be using an aftermarket head unit.

Car didn't come with one and all the stereo wires were hacked off, so I hooked everything up to a replacement plug and removed the rear speakers and amps in preparation for new speakers.

Front speaker were junk hacked into place and their wires were missing, so those need new wiring when I pull the dash this week.

My '93 90 Quattro has two antenna connections, but according to the Bentley wiring diagram, the front one is AM and the rear one FM, so most of us will probably only use the rear one. I'm not sure if they were optional and not sure about the ground since mine has the two antenna connectors (that look a lot like RCA connectors) and no ground wire with them.