Hey folks, I need help identifying a wire in the console. I'm trying to install a new Retrosound Model Two radio in my 1975 coupe (automatic transmission, with air conditioning). It requires a 12v constant wire to go along with the ignition/accessory wire and the ground. As we know, the stock radio used the ignition/accessory wire, the illumination wire, and the ground, so not an exact match.

It was suggested to me by someone familiar with older car electrical systems, but not Corvettes specifically, that I could use the constant from the cigarette lighter. That sounded like a decent idea.

However, without going into the long story, I inherited this car from my mother when she passed away, and it had sat in her garage undriven since 1991. Point is, whoever had the car before her did some hacking of the wiring around the radio and the shifter column. They replaced the stock radio with a mid-80's tape deck (it's wires didn't match either) and I am amazed that thing worked the way it was installed. Plus, it also explains why the instrument panel never fully lit up at night when the lights were on. But I digress...

I've figured out most of what they did, but I am at a small loss on the cigarette lighter wiring. From what that other guy told me, I expected to find a ground wire and an orange constant wire attached to the lighter. However, when I pulled up the shifter console, all that was attached was a ground wire. This actually matches the instructions the old Haynes manual I have (also inherited from my mother) gives for removing/installing the lighter, as it only references removing a ground wire.

Near the lighter, there was an disconnected orange wire with a black female connector on the end. See picture of lighter illumination wire (left), mystery orange wire (center), and lighter ground wire (right) at this link: https://www.dropbox.com/s/5y0l1i78d8...43.54.jpg?dl=0

Should this orange wire have been connected to the lighter somehow? Or something else? The connector on this orange wire is the exact same as the one on the orange wire that hooks into the clock. I'd like to make sure this is the lighter wire and not something else, since I will need to cut and splice it to the new radio. I have no problem losing the cigarette lighter as I am replacing it with a combo USB/aux port that is made to fit in the lighter housing. If this is not to the lighter and I need to hook that up to something else, then does anyone have suggestions on how to get a constant 12v to the Retrosound radio?

Also, bonus points to anyone who can identify the disconnected pink wire/connector that is seen just to the left of the ground wire, next to the A/C control, as well as the purple/white stripe and pink/green wires coming out of the same bundle that the lighter wires are coming out of.

Thanks in advance!

 

The black connector with the orange wire in your picture is the lighter connector... it's 12 volts all the time.


The lighter had a ring ground under the retainer as shown in the picture below.

Willcox

 

Thanks. If that is the case, then I'm now curious where the ground wire went, as there were no other wires in the assembly going to the lighter, not even to a ring.

The fun of a hacked up wiring setup...

 

I am also still very curious why I have unconnected wires (the orange one with the black connector, as well as the pink one with the larger connector) in the housing.

 

Not sure what the pink wire is for, I've not pulled a schematic on it. But odds are the lighter shorted out and so they just unplugged it which is common since it is 12 volts hot 24/7.

Have you though about just running a memory wire to the fuse box? You can pick up 12 volts constant on the accessory lug.

Willcox

 

Isn't the black wire with the female lug the ground wire that connects to a lug that is screwed to the underside of the console plate?

 

The black wire in my picture was connected to the bottom of the lighter.

 

Adam- I made a typo above.. I've corrected it. The orange wire with the black connector is what should have 12 volts at all times. The black wire is possibly the ground wire for the heater control assembly. Either way I'd probe them both for power. The orange should be the hot one.

Willcox

 

That makes a lot more sense. Like I said, the wiring has been moved around, and I am trying to straighten it out. Along with this, half the illumination bulbs in the instrument panel were empty, and the wiring for the fasten seat belt, headlamp, and door ajar indicator light were all mixed up (and empty of bulbs) when I pulled the instrument panel.

My best guess is the ring ground broke, and they just re-wired it to the bottom of the lighter, leaving the orange unplugged for some reason.

Of course, then the next big question is WHY they did all this. Hopefully this wasn't some convoluted effort to get around a short somewhere and by straightening everything back out to where it started, I am recreating the problem...

 

Would the 'BAT' lug be a better choice for the radio memory?

 

Yes... Yesterday was a long day for me Pete.

 

Here is the factory 1975 Wire Schematic. If you right click on the picture below and then hit copy, the open your paint program and paste it in there... you can use this as a tracer schematic which makes isolating circuits very easy.

I don't have them all on the tech site yet but I'm getting closer.

Willcox