AM/FM radio and wire identification

[DrillNFill]

Hi everyone,
I finally got around to pulling out the sorta/maybe/non-working AM/FM radio out of my '70 Dart I got in 2020. It is not the original radio as I later found out Darts didn't have one till '73 or so, so someone in the past added this in. Its fine with me it fits perfect in the non-rally dash and is period correct (as far as I'm concerned), but the FM doesnt seem to work at all and the AM sporadically at best. I'm going to send it to the repairman who salvaged the stereo in my old Chevy but I was hoping to first find the radio model number and see what wires are what coming out the back to aid with reinstallation. (I pulled the radio out from under the dash but couldnt see what wires were connected where)

There's several wires spliced in that are non-original from whoever installed it in the past. The red and orange wires have a plug end and that's easy enough to reconnect. The green wire was spliced to an orange wire, couldn't see what that was connected to but I can resplice it when installing. The black wire was spliced to another wire which disconnected itself from wherever while I was removing the radio. Again, I couldn't see what it was connected to.

Can someone educate me on what the red/orange, the green, and the black wires are? Is black the ground, red/orange power, and green the speaker? Id like to do better/ cleaner wire connections when re-installing. I tried googling the model radio to find out more info (because I feel stupid asking) but I cannot identify the model radio I have. Its a Motorola but couldn't find out any more info.

Id be grateful for more info, thank you all !

 

[krazykuda]

Red is the power wire....

Orange is the light power, it will dim or brighten the lights...

 

[Super-Cuda]

I'm pretty sure here's how they are wired. Green and black are speaker. Red is power, orange as stated is dial illumination and brightness. Funny thing though is that there is no brand id on the scale. Usually says Dodge, Plymouth or Chrysler.

 

[67Dart273]

Interesting..........both transistors mounted on the front corners have been replaced with more modern types

 

[4spdragtop]

Hey Al, I never noticed the lack of "brand" on the scale before. I wonder if its am/FM specific.
Heres our factory 67. That might be what the op has. To the right person that is a very high $$ radio.

I'm pretty sure here's how they are wired. Green and black are speaker. Red is power, orange as stated is dial illumination and brightness. Funny thing though is that there is no brand id on the scale. Usually says Dodge, Plymouth or Chrysler.


View attachment 1715852357

 

[Cuda Al]

Keep in mind that these early AM/FM radios were NOT stereo.


Alan

 

[billccm]

Bendix radio. I have the factory service manual for the early series. Repaired many over the years and have one being shipped to me now for repair.
These are AM radios that have kludge FM as a quick and dirty after thought. FM performance is far from good. I actually hate working on them as the FM PCB and tuner are a bear to take out and repair.
Not sure when the audio amplifier transistors changed from TO3 to TO220, but each are robust and reliable.

 

[DrillNFill]

I'm pretty sure here's how they are wired. Green and black are speaker. Red is power, orange as stated is dial illumination and brightness. Funny thing though is that there is no brand id on the scale. Usually says Dodge, Plymouth or Chrysler.

View attachment 1715852357

Both green and black wires go to the speaker? Car only has one central dash speaker.
There is a tiny Pentastar under the "15" between 102 and 108 FM

Keep in mind that these early AM/FM radios were NOT stereo.


Alan

Yeah I figure sound wont be great, id just like to hear something while I cruise

Bendix radio. I have the factory service manual for the early series. Repaired many over the years and have one being shipped to me now for repair.
These are AM radios that have kludge FM as a quick and dirty after thought. FM performance is far from good. I actually hate working on them as the FM PCB and tuner are a bear to take out and repair.
Not sure when the audio amplifier transistors changed from TO3 to TO220, but each are robust and reliable.

Do you have a model number? I was googling "Motorola PD2509" since that was on the label underneath.


Also, I noticed when the AM decided to work occasionally, there was interference with the engine speed. I know there's noise supressors built into the car, who knows after 50 years if theyr'e intact. Would my radio guy be able to install a noise surpressor into the internals of the radio itself? He's already going to add an aux cable wire I can route under the dash. Is internal noise surpression even a thing?

 

[Super-Cuda]

Both green and black wires go to the speaker? Car only has one central dash speaker.
There is a tiny Pentastar under the "15" between 102 and 108 FM


Damm! totally missed that! Good eyes!!

Speaker has two terminals I beleive.




Yeah I figure sound wont be great, id just like to hear something while I cruise



Do you have a model number? I was googling "Motorola PD2509" since that was on the label underneath.


Also, I noticed when the AM decided to work occasionally, there was interference with the engine speed. I know there's noise supressors built into the car, who knows after 50 years if theyr'e intact. Would my radio guy be able to install a noise surpressor into the internals of the radio itself? He's already going to add an aux cable wire I can route under the dash. Is internal noise surpression even a thing?

 

[cudamark]

Agreed, red is 12V + power lead, Orange is 12V light power lead, Green is speaker +, Black is speaker -. The radio itself grounds through a support bracket attached to the radio housing and dash frame. For the radio to work properly, you also need a good antenna that is also grounded properly.

 

[Demonic]

What Cudamark said. Often, the antenna grounding or inner cable is bad, which often results in bad AM and no FM.

 

[4spdragtop]

This is just my opinion. I wouldnt invest too much $$ in it. We had ours repaired and it wasnt cheap, although they did great work. In the end the factory radio only produced what...5 watts MAYBE. And someone mentioned it's not stereo either(single dash speaker).
IF you spend $$ put it into a "hidden" system with the front dual speaker bracket for the factory look. That's my plan anyway, my .02.

 

[4spdragtop]

Heres link to repair I did on our 67. Gotta click on links for pics to show.
67 antenna repair

Agreed, red is 12V + power lead, Orange is 12V light power lead, Green is speaker +, Black is speaker -. The radio itself grounds through a support bracket attached to the radio housing and dash frame. For the radio to work properly, you also need a good antenna that is also grounded properly.

What Cudamark said. Often, the antenna grounding or inner cable is bad, which often results in bad AM and no FM.

 

[str12-340]

took all of my original radios from my 3 Darts to Retro Radio restoration in Pennsylvania. Mom and Pop operation that restores radios as original, but also installs modern internals in your old radio - AM/FM stereo that accommodates 4 speakers, input for MP3, disc player, etc, even Blu tooth if you're into that. Excellent sound and looks completely stock because what you see is stock... Not cheap.

 

[DrillNFill]

I'm pretty sure here's how they are wired. Green and black are speaker. Red is power, orange as stated is dial illumination and brightness. Funny thing though is that there is no brand id on the scale. Usually says Dodge, Plymouth or Chrysler.


View attachment 1715852357

I just noticed in the photo you posted the black and green wires are joined by a plug at the end. When i removed mine, there was an unused gray plug hanging from behind the dash plugged into nothing. I wonder if my radio (of indeterminate year) originally had a plug at the end of the black and green wires that didn't jive with the 1970 plug in my car.

Thanks again for the help everyone

 

[4spdragtop]

The factory used a grey wire for a tach "up in there" for a rally dash.
It went to "J" in bulkhead connector
Pics