Radio Wiring and Amp Bypass

[petercory]

After carefully following the E30 Premium Sound System Amp Bypass instruction posted by numerous forum members throughout this thread and isolating the ground wires at the 17 pin connector, my CD43 Business CD would still not transmit sound through the original Speakers. All of the Speakers tested good @ just under 4 ohms. Fortunately "bradnic" had the patience to explain why the "Cut & Cobble" procedures weren't a proper solution, I purchased his Bypass Adaptor and wiring kit for the front Speakers; once installed, my system functioned perfectly. I could have saved many hours of wasted time and frustration had I purchased a "Kit" from bradnic to begin with.

[petercory]

No, I've done the Amp Bypass

[bradnic]

used this and worked absolutely perfect in my 91 325i coupe with premium sound and no fader, perfect amp delete write up and sounds fantastic > thanks guys

here’s the work> piece of cake (00=00)

Really wish folks would stop cutting 30+ year old OEM audio wiring. I have bypass adapters now - just plug in to the amp connector and instant bypass. Also have access harnesses to run aftermarket amps, subs etc.

[bradnic]

petercory are you running the factory amplifier?

[petercory]

I just pulled the Sony Head Unit out of my '90 Conv. and found that the Speaker Grounds were not connected to the Head unit; all (4) were connected together and not grounded to anything. I have completed the Amp Bypass and now I'm planning to install a CD43 Business CD. Should I leave the Speaker Grounds the way they currently are, connect them to a common ground or attach them to the corresponding ground wire on the CD43 Business CD Harness or are other changes required?

[SPOautos]

Hello! Newbie here....I'm planning before taking apart my wife's 1991 convertible. Does anyone know the gauge of the factory power wire and fuse going to the trunk amp? Would it support a 4x75rms aftermarket amp?


Thanks for any info!

[petercory]

No, I haven't changed any of the Speakers. Do I have to change the kick Panel speakers or will a wiring change solve the problem?

[bradnic]

Have a '90 Conv W/Premium Sound & no Fader. I've done the Amp Delete Bypass. The Kick Panel & Rear Speakers work ok, but the Tweeters just have a low pitched noise when the other speakers sound normal. Do the Tweeters have to be re-wired?

Did you change the front kick panel speakers? They have a crossover on them for the tweeters

[petercory]

Have a '90 Conv W/Premium Sound & no Fader. I've done the Amp Delete Bypass. The Kick Panel & Rear Speakers work ok, but the Tweeters just have a low pitched noise when the other speakers sound normal. Do the Tweeters have to be re-wired?

[e30mobber]

used this and worked absolutely perfect in my 91 325i coupe with premium sound and no fader, perfect amp delete write up and sounds fantastic > thanks guys

here’s the work> piece of cake (00=00)

[PNWE30M50]

Thank you everyone! This thread really helped me. I wanted to try and help others in return and thought maybe a video could do that.

Posts #91 and #448 were my go to.

I have a 1987 325es, CM5907, premium sound, fader in dash (6 wires), and a stock amp in the trunk. Went with a Continental TR7412UB-OR, bypass stock amp/repurpose fader wires, rewire fronts/tweeters.

Please let me know if you see something I did wrong so I can fix it!!! I am also garbage at talking while filming...so sorry in advance.

https://www.youtube.com/watch?v=lXYdEnJJVnU

[nando]

Finally snagged a KE83ZBM that isn't completely ragged! It probably still needs caps, a new drive belt, and to get the CODE from the dealer, but it looks to be in decent shape and the screen is good.

So now, do I really want an OE amp? It's been a long time since my stereo was stock - it wasn't that great that I remember. What's a decent drop in replacement for the 4-channel bypass? Maybe 5 channel, if I want to add a sub one day, but I'll just run stock speakers for now. I don't want to cut into the wiring more than is done already, but I could easily print my own housings/adapters..

I finally plugged it in. Needs one of the lights on the LCD replaced, but otherwise it seems like it's really clean and functional.

Once I get the CODE from the dealer, I'll get to fixing the wiring for the amp. I'm thinking I'll just skip to an aftermarket 5 channel, since I don't have a stock one anyway.

Also my original antenna mast still works! I had to clean and lube it and run it up and down a few times, but I was afraid it might be toast. I probably haven't used it in 10 years.

[nando]

Finally snagged a KE83ZBM that isn't completely ragged! It probably still needs caps, a new drive belt, and to get the CODE from the dealer, but it looks to be in decent shape and the screen is good.

So now, do I really want an OE amp? It's been a long time since my stereo was stock - it wasn't that great that I remember. What's a decent drop in replacement for the 4-channel bypass? Maybe 5 channel, if I want to add a sub one day, but I'll just run stock speakers for now. I don't want to cut into the wiring more than is done already, but I could easily print my own housings/adapters..

[bradnic]

Did this diagram work for you? I have an early build 1990 with premium sound and no external fader.

Thanks!

There are both 2channel and 4 channel amp bypasses. The 2 channel amp bypass has fewer wires, so that table won't work for it. fully explained in the first post here https://www.r3vlimited.com/board/for...and-amp-wiring

[bradnic]

I have completely updated the E30 speaker and amp wiring thread. Should help folks a lot with understanding what they need to do.

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