Does anyone have a good source for buying a radio wiring conversion harness to go from my 1970 Cutlass Supreme wiring to the new radio wiring? The guy at the auto parts store implied this stuff is easy to find, but I cannot find one website that talks about this. You know, you tell them what car you have, the radio you are buying, and they tell you which harness to buy. I don't want to cut the wires. Please help.

 

You're not finding anything because there's nothing to find. The guy at the auto parts store is probably used to dealing with people who are putting a new radio into a modern car. That's not the case here.

All you need is the wiring diagram "pinout" for your modern radio, and that should be in the manual that came with it. A 1970 Cutlass's audio system wiring is very simple compared to modern systems.

Find the wires coming from the radio that go to the left front speaker (assuming you have a left front speaker in your car), and connect the positive to positive and the negative to negative. Ditto for the other three speakers.

Find the new radio's wire that gets 12 volts switched and connect that to the 12 volt switched wire that would go to the original radio. An original radio would not have had an "always on" wire because radios back then didn't have electronic clocks or electronic presets, so you'll have to connect the "always on" wire coming from your new radio to an always on power source at the fuse box. The wire that would go to a clock or cigarette lighter would work as well as those are always powered in your car. Make sure the new radio's ground wire is connected to a good ground.

And that's it. I put a modern Alpine radio in my '73 Custom Cruiser, and this is exactly what I did. I used my wire cutters, wire strippers, and electrical tape, and I tucked everything up and out of the way.

Yes, there's a small plug that goes into the factory radio, and you'll have to cut that off and make connections to the individual power and speaker wires, but that's no big deal.

The kind of wiring harness adapter you're talking about is what you'd need if you were trying to put an aftermarket radio into a modern car that has one of those multi-pin connectors going into the back of the radio. But that's not the case here. You don't need any such adapter, and there probably isn't one made, anyway, as it's not needed.


Here's my radio in the dash. It looks great, sounds great, and I have AM/FM/CD/satellite radio/Pandora, and USB and AUX ports. Plus a clock that actually keeps time.

 

+1.

There is no real wiring.

Yellow is hot with the ignition or accessories on.
Grey is hot with the panel lamps (and it dims).
Black is ground.

There was no electronic memory in radios then, so there was no "constant on" wire - you have to get it from the BAT tap on the fuse block or any other site of your choice.

The '70 antenna is in the windshield, so there is no power antenna connection.

Most '70s had AM or AM/FM radios, with a single speaker in the center of the dashboard - you're probably not using that anyway.
Some had the optional rear speaker, with an add-on fader control on the right stalk.

Some cars had stereo radios, and I believe that '70 Cutlii still had a single front speaker with those, but got two in the back. How you use or do not use this arrangement is entirely up to you, and beyond the scope of an "adapter plug."

Oh, the way that an Olds radio mounts in the dash is different from the way a modern radio mounts - please don't destroy your dashboard mounting it. Good ones are getting harder and harder to find.

Welcome to ClassicOlds.

- Eric

 

This is true for any radio back then, not just Oldsmobile-labeled radios, and it was true up through the early '80s. After that, the "DIN" standard for audio component openings in automobiles came into use, and we still use them today..

http://en.wikipedia.org/wiki/ISO_7736



And, yes, I did cut into my dash to make my radio fit. Sue me.

 

New audio equipment comes with a harness and as previously mentioned it's not very difficult to install.

 

Yeah, but that was for a '73. That's not even an old car.

I cut the p__s out of mine, too (after laying away a nice spare from the junkyard ).

- Eric

 

Specifically, it comes with something like this.




The white plug goes into the back of the new radio, and the individual wires are connected to the speakers, power supply, and ground. There are often extra wires on a new radio that you won't use. Things like a power antenna lead, wires that would connect to the controls on your steering wheel, and that sort of thing.


An "adapter" as the OP is talking about would be the reverse of this. The white plug would plug into the connector in the car's wiring harness, and then individual wires coming from it are spliced to the individual wires coming from the radio's connector. There's no way to get around the need to strip wires (note that, in the photo, they're "pre-stripped"), connect wires and wrapping wires with tape or some other form of insulation.

 

Guys, thank you so much for the replies. Let me offer a few more items:

1. I DO NOT want to strip my wires and the connectors currently going into my radio. I simply would like to find an adapter that will connect to those, and then out the backside contain the necessary connectors to go to the new radio. If that does not exist, then perhaps I should invent that. Seems to simple. Does anyone know if this kind of adapter exists??

2. I DO NOT want to take the original radio out. I will build some sort of mounting bracket to mount it under the dash or build a vented box to sit on the tranny tunnel.

 

Can you post a pic of the end that plugs into your radio?
I don't have a factory radio or harness in my car for reference.

 

Does it look like this?
http://www.ebay.com/itm/1963-1970-Ol...-/380557254602

If so, you could crimp male spade terminals onto the new radio harness and insert them into the proper locations on your factory harness. Wrap it in electrical tape and you should be good to go.
You will need an extra connection/wire from the fuse panel for +12volt constant of the new radio.
I'm not sure how the negative line of the factory speakers are run, since I only see 3 wires in this harness.

 

I seriously doubt that there will be an adapter harness available for your application. There was none when these cars were new that I know of. We generally ran new wires and left the old harness dangling intact. There are too many differences between the old radio requirements and an aftermarket one. You need to consider the number of, and impedance requirements for the speakers. Power requirements for memory as Eric mentioned above. Some old style speakers used chassis ground for the negative terminal. It may be better to just use new wiring and leave the old intact.

If your dead set on trying, I would find a parts radio and remove the connector from it and fabricate your own adapter using the harness that comes with your new radio. I can tell you from experience that there is no way to 100% accomplish your scenario.

 

No, but I DO know that it does NOT exist.

- Eric

 

Why bother with all this? If you don't want to cut into your existing wiring, then run new wiring from the new radio to the speakers and to switched and unswitched power sources on the fusebox. Why is it so important to use the wiring that goes into the back of the existing radio? Just leave it plugged into the radio you're leaving in the dash.

As others have said, no adapter such as you're looking for exists because there is no demand for it. Audio systems of that vintage typically were an AM radio that had a single power wire to the radio, a ground wire, and two and sometimes only one wire going to a single speaker (where the body of the car itself was used as the "return" speaker wire). Why would anyone want to connect that to a modern radio? It wouldn't work, anyway.

Anyone putting in a new radio is also likely installing two or four new, modern speakers. If you're going to the trouble to put those in, it's no additional effort to run wires to them and carefully route and conceal that wiring.

 

Leave the old radio intact with all its wiring. There is no known adapter made for the vintage GM to new aftermarket radios. May I suggest you also look at this thread if you're interested in mounting another radio? Gauge and Stereo Housings

No - that's the repair connector for an OEM radio - not a bridge to a new one.

Exactly. Old system is very simple and must have 10 ohm speakers.

The correct answer, as usual.

This ^^^, same as Eric and Eric have said.

 

Ok. I confirmed with a local company in business 25 years that in fact no such adapter exists. I was trying to avoid the mega nightmare like last fall, in getting my in-dash clock to work, which I did after hours and hours and hours. Why no where in any manual does it say that the body of the clock actually needs to be touching metal on your car for it to actually work (the body of the clock actually grounds on the car). Oh well, I guess I just dig in. Thanks all.

 

Oh, self inflicted ignorance, that's why they call chassis ground. Just wait until you tackle the radio..

 

Because electric circuits operate on the principle of a constantly moving electric current (flow of electrons), and not on the principle of static electricity, where a bunch of electrons move from Point A to Point B and then just stay there.

In order for you to have an electric circuit, the current has to flow into a device, through the device, and then out of the device.
Any device designed with only one wire connected to it (like many of the devices in our cars) will not work unless grounded, so that the electric current can return to the battery through ground.

Interestingly, if you look in newer workshop manuals, most if not all of them DO make this point explicitly at the beginning of the electrical section, indicating that what used to be considered common knowledge is now something that needs to be explained.

- Eric

 

You mean to say the grounding straps on the dash were missing? That's really unusual because all the lower dashes were built with the same ground connections, and grounded out onto the dash subframe.