Hi Guys I've searched this thread and gone back to 2007 but hav'nt found the right answer, I have bought an aftermarket radio for my 95 300es I have put the power and speaker plugs in the new radio and all works fine, but how do you wire up the sub woofer in the rear door there is a narrow plug that fits vertically in the back of the old radio this is the line out to the the back door, there is a black and red wire coming from this plug and both going into the screened insulation, the question is are these cables left and right output cables which are grounded by the car chassis, and I can convert to RCA plugs and plug into the line out on the new radio , or is the red one power out and the black the earth therefore I will have to wire it accordingly, also were is the power for the sub amp coming from is from the ignition or do I have to link some cables that are in the multiplug the that feeds power to the head unit as there are 8 power inputs in the factory radio and only 4 in the new one in other words doe's the factory radio switch on the sub amp in the boot. Any help would be appreciated, many thanks.
discool
Well-Known Member
For the audio make up a patch lead, the head units sub pre-amplifier output + - will be common for a mono sub. so the screens will terminate to the black wire and both the center conductors will terminate to the red wire. The power for the sub amp is from your head unit and is already in the iso plug.
Thats what I did, and there's lot of info on installing head units in the Forum
Thats what I did, and there's lot of info on installing head units in the Forum
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wingers1982
New Member
yes you need a remote switch on for the amp it's usually blue or if you dont have that you could use the power Ariel feed as that does the same job and thats usually blue and white the red is power and the black is earth and if you dont have enough power cables to supply it run another power cable to the old wiring from the new wiring
discool
Well-Known Member
Had this very problem.Connect red and black wires together and connect to centre pin of phono plug that connects to sub out on your radio.
Sub amp has a permanent 12V feed and is turned on and off by the radio in a similar way that it would operate an electric aerial
pauli, the sub amp in the back door has two feeds one permanant and one switched.
discool
Well-Known Member
Morning all
First off I got a bit confused yesterday.I looked back on what I did to get my sub working (with Discools help at the time )
The sub audio feed is in fact a whats called a balanced feed that reduces noise pock up on the run to the sub in the back.If your radio has a phono socket sub output you connect the red to the centre pin on a phono plug and the black to the outer (earth) on the plug.This will unbalance the feed but it will work fine.
My aftermarket Kenwood had an aux 12V output that is used to switch the sub amp on and off with the radio
Hope this all makes sense now and apologies for talking rubbish yesterday
First off I got a bit confused yesterday
.I looked back on what I did to get my sub working (with Discools help at the time )The sub audio feed is in fact a whats called a balanced feed that reduces noise pock up on the run to the sub in the back.If your radio has a phono socket sub output you connect the red to the centre pin on a phono plug and the black to the outer (earth) on the plug.This will unbalance the feed but it will work fine.
My aftermarket Kenwood had an aux 12V output that is used to switch the sub amp on and off with the radio
Hope this all makes sense now and apologies for talking rubbish yesterday
discool
Well-Known Member
Thats ok, some head units do. mine has three, bass, mid and high. You do know that all the pre-amp outputs are in pairs, left channel and right channel.
gizgrey
New Member
i have a kenwood head unit i plugged the power and speaker connections into the kenwood multi plug,then put the red amp wire to elec antenna wire and put black to stereo earth...what did i do wrong..and how can i fix it..i have pro outs for amp at back but havent got the connecters to plug in.
discool
Well-Known Member
I take it u wish to connect your Kenwood head unit to the rear door sub amp it that correct.?
