Rewiring Factory Radio in 70 Cutlass Supreme
February 17th, 2012, 08:56 AM
#1
Registered User
Thread Starter
Join Date: Jan 2012
Posts: 4
Rewiring Factory Radio in 70 Cutlass Supreme
Hello,
I have an 1970 Cutlass Supreme "Holiday Edition" that I purchased this past summer. The exterior is as ugly as sin, but mechanically incredible (exhaust never smokes - even on a cold start in winter!) and the guy I bought it from had just redone the interior, or rather most of it. At one point he had installed his own sound system or had planned to and had unplugged the original AM radio. I am getting a little tired of driving in silence and would like to hook the AM-Radio back up. The radio is still installed, it just doesnt have any wires connnected.
Before we get into the wiring, I have a quick dumb question. The radio is the old-school olds AM radio, two dials, five or six buttons in the middle. No obvious speakers. Simililarly there are no obvious speakers in the door panels. There are no speakers behind the back seat, though it is pretty torn up back there so there could have been speakers at some point. My question is, does this radio have some sort of internal speaker, or will I have to install new speakers? Second, if there is no output for speakers would it damage the radio at all to turn it on once it is wired? I know that sounds odd but I remember someone warning me about this as sometime, and I dont know if it is true.
Looking under the dash, I can see some loose wires coming off of the radio, and some loose wires just hanging around. I assume that they can be matched up in such a way that the radio will work, I just dont know how. And I dont want to start connecting wires for fear of starting a fire (As a teen I made this mistake and I kid you not set my computer on fire).
I took some photos to illustrate the problem, I hope there are some standard factory color coding for the wires otherwise these may not be much use.
photo.jpg
This first image is probably the simplist issue. The plug shown fits into the back of the radio. I assume this is the power. The blue and black wires are connected fine, but you can just barely see that the yellow wire was clipped at somepoint. Also in the photo you can see a yellow wire hanging loose. I assume that I need to rewire this wire into the plug. Is that a safe bet?
photo2.jpg
This photo is of the passenger side of the radio. There is one blue wire with a plug coming off of here. What is this wire for? Speakers, antenna, power?
photo1.jpg
This photo is of the driver side of the radio, here we can see it is a mess. Some of the wires go elsewhere, the orange one for example has nothing to do to the radio as far as I tell, The thick cable which you cant see the end of has a big silvery plug on the end, which makes me suspect it is the antenna, but I havent looked closely.
Any advice you can give me before I unplug the battery and rewire this would be welcome. Thanks,
Ben
I have an 1970 Cutlass Supreme "Holiday Edition" that I purchased this past summer. The exterior is as ugly as sin, but mechanically incredible (exhaust never smokes - even on a cold start in winter!) and the guy I bought it from had just redone the interior, or rather most of it. At one point he had installed his own sound system or had planned to and had unplugged the original AM radio. I am getting a little tired of driving in silence and would like to hook the AM-Radio back up. The radio is still installed, it just doesnt have any wires connnected.
Before we get into the wiring, I have a quick dumb question. The radio is the old-school olds AM radio, two dials, five or six buttons in the middle. No obvious speakers. Simililarly there are no obvious speakers in the door panels. There are no speakers behind the back seat, though it is pretty torn up back there so there could have been speakers at some point. My question is, does this radio have some sort of internal speaker, or will I have to install new speakers? Second, if there is no output for speakers would it damage the radio at all to turn it on once it is wired? I know that sounds odd but I remember someone warning me about this as sometime, and I dont know if it is true.
Looking under the dash, I can see some loose wires coming off of the radio, and some loose wires just hanging around. I assume that they can be matched up in such a way that the radio will work, I just dont know how. And I dont want to start connecting wires for fear of starting a fire (As a teen I made this mistake and I kid you not set my computer on fire).
I took some photos to illustrate the problem, I hope there are some standard factory color coding for the wires otherwise these may not be much use.
photo.jpg
This first image is probably the simplist issue. The plug shown fits into the back of the radio. I assume this is the power. The blue and black wires are connected fine, but you can just barely see that the yellow wire was clipped at somepoint. Also in the photo you can see a yellow wire hanging loose. I assume that I need to rewire this wire into the plug. Is that a safe bet?
photo2.jpg
This photo is of the passenger side of the radio. There is one blue wire with a plug coming off of here. What is this wire for? Speakers, antenna, power?
photo1.jpg
This photo is of the driver side of the radio, here we can see it is a mess. Some of the wires go elsewhere, the orange one for example has nothing to do to the radio as far as I tell, The thick cable which you cant see the end of has a big silvery plug on the end, which makes me suspect it is the antenna, but I havent looked closely.
Any advice you can give me before I unplug the battery and rewire this would be welcome. Thanks,
Ben
Last edited by bmichener; February 17th, 2012 at 10:05 AM. Reason: Broken Photo Links
February 17th, 2012, 09:09 AM
#2
Lansing built
Join Date: Nov 2011
Location: Grand Ledge, MI
Posts: 3,227
pics
Your pics did not show up! you probably have a single speaker in the center of dash AKA deluxe push button radio AM mono, that is what I have.
given that you have wires hanging I would assume color to color, unless you have a real hack job? Let me know I think I can conjure up a diagram.
Pat
given that you have wires hanging I would assume color to color, unless you have a real hack job? Let me know I think I can conjure up a diagram.
Pat
February 17th, 2012, 09:15 AM
#3
Registered User
Join Date: Feb 2008
Location: Plano, TX
Posts: 11,798
You should have a 4x10" speaker in the center of the dash. It is probably there, whether it works is the next question.
That was the only one unless the rear speaker option was added. it looks like yours did not come with it.
Your pictures did not come through, so maybe try again.
However I do know the yellow is the 12V feed to the radio.
The blue and black in one plug should be for that dash speaker.
The thick black cable should be an antenna cable. this most likely feeds a windshield antenna and the connection may be broke at the glass if you get no reception.
The single blue wire would go to the rear speaker positive terminal if you wired and installed one. The negative would be chassis ground. If you do not see a loose blue wire coming from over the heater box, your car was not wired for the rear speaker.
The orange one does not go to the radio. If it is factory wiring, it would be 12V constant for cigar lighter, courtesy lights, or clock...
That was the only one unless the rear speaker option was added. it looks like yours did not come with it.
Your pictures did not come through, so maybe try again.
However I do know the yellow is the 12V feed to the radio.
The blue and black in one plug should be for that dash speaker.
The thick black cable should be an antenna cable. this most likely feeds a windshield antenna and the connection may be broke at the glass if you get no reception.
The single blue wire would go to the rear speaker positive terminal if you wired and installed one. The negative would be chassis ground. If you do not see a loose blue wire coming from over the heater box, your car was not wired for the rear speaker.
The orange one does not go to the radio. If it is factory wiring, it would be 12V constant for cigar lighter, courtesy lights, or clock...
Last edited by Lady72nRob71; February 17th, 2012 at 11:17 AM. Reason: updates after pics showed up
February 17th, 2012, 09:40 AM
#4
Connoisseur d'Junque
Join Date: Sep 2010
Location: The Hudson Valley
Posts: 21,183
To add to what Rob said:
Yellow: Hot
Black: Ground
Grey: Panel lights
They should go into a plug that plugs right into the back of the radio.
If the center speaker isn't in the middle of your dash, you'll have to get a new one. They tend to get destroyed over 40-odd years in the sun, but you may be able to find a used one that someone on here removed.
Finally, DO NOT turn your radio on without the correct, working speaker attached - You will blow the output transistor. These GM radios seem to be very susceptible to that.
Also, keep in mind that the original GM speakers were 10Ω (not 8 or 4, like modern speakers). It might survive for a while with an 8Ω speaker, but 4Ω would definitely kill it.
- Eric
Yellow: Hot
Black: Ground
Grey: Panel lights
They should go into a plug that plugs right into the back of the radio.
If the center speaker isn't in the middle of your dash, you'll have to get a new one. They tend to get destroyed over 40-odd years in the sun, but you may be able to find a used one that someone on here removed.
Finally, DO NOT turn your radio on without the correct, working speaker attached - You will blow the output transistor. These GM radios seem to be very susceptible to that.
Also, keep in mind that the original GM speakers were 10Ω (not 8 or 4, like modern speakers). It might survive for a while with an 8Ω speaker, but 4Ω would definitely kill it.
- Eric
May 13th, 2017, 07:04 AM
#7
Registered User
Join Date: Sep 2012
Location: Illinois
Posts: 528
I'm installing an aftermarket radio manufactured by Antique Automobile Radio - stock appearance for Cutlass 70-72 with modern digital internal components. The radio provides a grey wire for the dial light and a black ground wire.
Many posts in several threads state that there is are dedicated wires for the radio under the dash with these colors: yellow = power, black = ground, grey = radio light dimmer. (Other wires are for the speakers.)
I cannot find a grey wire dedicated for the radio dial light, or a dedicated black wire for ground. The wiring assembly diagram also shows only the yellow (power) lead wire and wires for front and rear speakers. No grey or black wire is shown in the assembly diagram. Ground is apparently supplied by the metal grounding plate on the rear dash where the left side of the radio fastens to the dash. Can anyone confirm or clarify? If there is a dedicated grey and/or black wire for the radio, where is the location?
Appears as if the radio dial light was powered directly through the radio, not separately, and not through the dimmer / rheostat for the dash lights. Does the stock radio dial light light up once the radio is turned on?
Thanks.
Many posts in several threads state that there is are dedicated wires for the radio under the dash with these colors: yellow = power, black = ground, grey = radio light dimmer. (Other wires are for the speakers.)
I cannot find a grey wire dedicated for the radio dial light, or a dedicated black wire for ground. The wiring assembly diagram also shows only the yellow (power) lead wire and wires for front and rear speakers. No grey or black wire is shown in the assembly diagram. Ground is apparently supplied by the metal grounding plate on the rear dash where the left side of the radio fastens to the dash. Can anyone confirm or clarify? If there is a dedicated grey and/or black wire for the radio, where is the location?
Appears as if the radio dial light was powered directly through the radio, not separately, and not through the dimmer / rheostat for the dash lights. Does the stock radio dial light light up once the radio is turned on?
Thanks.
May 13th, 2017, 07:31 AM
#8
Administrator
Join Date: Oct 2009
Location: Poteau, Ok
Posts: 40,561
I believe some radios had a non dimmable self contained light that illuminated only when the radio was turned on. You can tap into the dash light circuit (gray wires) for lighting. You'll probably need both a switched power source (original yellow wire) and an unswitched for radio memory. Tie your black wire to chassis ground and wire your speakers. Do not tie your new speaker negatives to ground as they were stock.
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