Radio Wiring

Mudeblue

Well-Known Member
Joined
Jan 10, 2018
Messages
631
Reaction score
380
Location
Phoenix, AZ
Car is coming together and we are down to the finer details.

I am installing the original AM radio back in my 65 SF. Prior to the restoration, I had a digital radio, CD changer and amp in trunk. I am not putting this back and will worry about a sound system later.

The original radio has a red wire for power, orange for lighting and a black and green to the front speaker. In reading the Service Manual, the front speaker is not grounded and requires the black for ground.

My question, how is the rear speaker then wired given there is a front and rear adjustment on the radio?
 
Last edited:
On a mono radio, the base speaker output wiring goes to the fader first, where it is divided and modulated to each speaker. Double that on multiplex stereo radios.

On non-rear speaker vehicles, the output wiring goes to the speaker only.

On radios with rear self-grounded speakers, only the power wires go to the rear speakers. When using non-self-grounded (two terminals) rear speakers, just make a jumper wire from the "-" terminal on each speaker to a body sheetmetal ground. My 1980 Newport is that way, so I just made jumper wires that went to one of the speaker mounting stud nuts.
 
On a mono radio, the base speaker output wiring goes to the fader first, where it is divided and modulated to each speaker. Double that on multiplex stereo radios.

On non-rear speaker vehicles, the output wiring goes to the speaker only.

On radios with rear self-grounded speakers, only the power wires go to the rear speakers. When using non-self-grounded (two terminals) rear speakers, just make a jumper wire from the "-" terminal on each speaker to a body sheetmetal ground. My 1980 Newport is that way, so I just made jumper wires that went to one of the speaker mounting stud nuts.
Got sidetracked and have been addressing engine, brake, radiator, top, issues the last month and now getting back to the radio issue as we button the three year, complete restoration down.

After reading about rear speakers, reverbs, A/M, F/M, Bluetooth conversions, my plan of attack is to keep the stock radio(had a digital stereo for the last 30 years) put in a RediRad A/M Adapter linked to a NVX VUBT2 Bluetooth Receiver which I researched and now have the hard to locate pieces.

After plugging this into the mono radio, I will then run the speaker wire from the radio to a 100 amp I have had for 30 years and it works fine. From there, I will go individually to the front and rear speakers from the amp realizing I will not have a front and rear speaker balance option unless I put in a reverb or fader coming off the radio before the amp.

Sounds like a plan but the ditches are full of “good plans.” If all that fails, I will just have to invest in whistling lessons!
 
Last edited:
Got sidetracked and have been addressing engine, brake, radiator, top, issues the last month and now getting back to the radio issue as we button the three year, complete restoration down.

After reading about rear speakers, reverbs, A/M, F/M, Bluetooth conversions, my plan of attack is to keep the stock radio(had a digital stereo for the last 30 years) put in a RediRad A/M Adapter linked to a NVX VUBT2 Bluetooth Receiver which I researched and now have the hard to locate pieces.

After plugging this into the mono radio, I will then run the speaker wire from the radio to a 100 amp I have had for 30 years and it works fine. From there, I will go individually to the front and rear speakers from the amp realizing I will not have a front and rear speaker balance option unless I put in a reverb or fader coming off the radio before the amp.

Sounds like a plan but the ditches are full of “good plans.” If all that fails, I will just have to invest in whistling lessons!
With regard to my project I laid out above, my stock AM radio has a green and black output wires which run to the front speaker. I want to use these as inputs to the amp and use the left and right outputs from the amp to circle back to the front and rear speakers. I am using RCA cables and adapters along with splicing to accomplish this.

Having said that, I want to stay consistent with the “signal wire” going in and coming out of the amp. My Service Technical Manual is silent on which wire carries the signal.

I would assume that the green wire carries the signal and the black is the ground but other research sometimes contradicts this. I realize of course that if I was going from the radio to speakers, it wouldn’t make any difference and that may hold true here also. In my case,however, it might and given the complexity of what I am attempting, I am invoking the old cliche “an ounce of prevention is worth a pound of cure.”

Having said all that, does anyone know which of the wires, green or black, carries the signal or is this a lot to do about nothing?
 
Back
Top