Toty79

Hello to all friends of the forum and well found, congratulations on your forum.
I am struggling with a restoration of a Delco Gm car radio and from the research I arrived at your forum, I ask you for info (I attach photos) on this car radio, first of all what model is it?
And then you know what that connector with two wires on the back is for?
The diagram is silk-screened for the main connector but nothing is written in the one with two wires, thank you all

4R5

The 2 addtional wires - Red is constant 12V for the memory (and to keep the radio's processor runing for the clock, etc), and the brown wire is the parking lamp feed, which is live whenever the parking lamps or headlights are on. This signals the radio to dim its display for nighttime operation, and to further dim the display when you dim the dash lights.

Toty79

Thank you very much 4R5
I don't have the car so I have to connect everything to the bench, I just connected the red to the 12v + but I still have a display off, do I have to connect something else to the brown wire?
thank you

4R5

Try grounding the brown wire. It's been a while but I think the brown wire needs to be grounded to get the dispay to light up.

Toty79

4R5 I am very grateful for your information ..
grounded brown wire but still get a display off ..

4R5

OK, I'll need to check my notes, I'll try to get back to you by tomorrow evening.

Toty79

Thank you very much, I look forward to seeing you

matt69olds

There is a pinout connector diagram stamped in the radio case somewhere. The plugs are keys to fit only one way so its almost impossible to screw up.

What you are calling a red wire is actually orange. It needs power at all times, it keeps the clock going and presets stored with the key off. I’m pretty sure the radio won’t work without power on it.

The brown wire is taillight feed. It needs power with the headlights on, it dims the display. The radio doesn’t care if this function is wired.

The gray (dash lamps) wire provide power to the display backlighting. The radio will work without it.

Yellow is ignition power, it should have power with the ignition in run and accessory.

Light/dark green, light/dark blue, tan/gray, yellow/brown are speaker.

Pink is power antenna output.

Black is ground, the radio also ground thru the mounting case.


Look up Delco ETR 2700

4R5

What Matt said.... the brown does not have to be grounded. Does the radio turn on? And receive stations even though the display is out?

Toty79

Ok, thanks to everyone guys
the car radio is connected to the bench the main connector is silk-screened on the cover and then I soldered in the right places, I did not know only the function of the two-wire connector but you taught me their function

4R5 Yes the radio turns on but I have distorted audio on all channels, I thought I would repair the display first and then the audio, even with the tape the tape runs but I have distorted audio almost a hiss, I think due to lossy capacitors in the side power, but first I would like to understand the problem of the display, any advice is well accepted and thanks to all