Thread: 3.5mm aux input for Delco Stereo

For those who still finding a 3.5mm stereo or RCA connector aux input for GM/AC/Delco make radio, I did mine for the 03-04 Toyota Matrix/Pontiac Vibe with AM/FM/CD/Cassette radio featuring in many GM cars/trucks.
no name FM modulator....
What you need is a super small 12V DPDT relay, 3.5mm stereo jack or Red/White RCA connectors, soldering gun and little cursing. .

I have this whole thing figured out for '82-94 GM Delco UM6 and UX1 stereos. Heres the link: http://search.ebay.com/320201039890

Hey all,

Just thought I'd put my 2 cents in here. I've been working with delco units for several years. First of all, if you're looking to add an AUX input to an older unit, it's better to purchase a newer, but, classically styled head unit, like for example, GM part number: 16085414 or any of it's 3 piece in one cousins. These units have and amp/tuner box on top, a controller face in front, and the CD or Cassette player at the bottom and usually have a display with the Volume, Bass, Treb, Bal, and Fade indicators. These units are extremely easy to add an aux input to. All you do is simply wire it all to the cassette/CD input into the tuner box. This even has a 14 volt power out and power return which is used to shut the radio off via an internal relay. It is commonly marked as "T-On." Line ins are also true line ins with no modification needed much like a home system. Just add your input jacks and a way like a switch or something to send power back to the "T-On".

Also, these units do not require a tape in the tape deck when this true "AUX" input feature is used. These radios simply display "Stereo" in the display as oppossed to "Tape" or "CD." Audio quality is perfect and it just works. This is also standard for the 3 piece cousins such as those radios used in GM CK Trucks, Pontiac Grand Prixs and Sunbirds, and Buick Regals. You can also use the "Stop-Play" button on these units to switch between your auxillary devices.

I hope this helps you all,
Starflare5.

Hi,

I am new here, and trying to solve this same puzzle as everyone else. Starflare5 most accurately describes my situation, but I have a couple of questions. I want to know if I can splice directly into the left/right/ground wires from the cassette deck, or if I need to isolate them with some sort of a relay. I don't know if the electricity coming from the IPOD (Or anything else I might connect to this jack) will ruin the pre-amp of the cassette deck. My plan is to wire in a relay in conjunction with a switched 3.5 mm plug to activate the plug when something is inserted. I want to be able to use both the cassette deck (if I ever wanted to) and the IPOD jack. Has anyone else done this? Does anyone else have any input?

Thank-you,
Christopher

Originally Posted by ostranderbrown1

Hi,

I am new here, and trying to solve this same puzzle as everyone else. Starflare5 most accurately describes my situation, but I have a couple of questions. I want to know if I can splice directly into the left/right/ground wires from the cassette deck, or if I need to isolate them with some sort of a relay. I don't know if the electricity coming from the IPOD (Or anything else I might connect to this jack) will ruin the pre-amp of the cassette deck. My plan is to wire in a relay in conjunction with a switched 3.5 mm plug to activate the plug when something is inserted. I want to be able to use both the cassette deck (if I ever wanted to) and the IPOD jack. Has anyone else done this? Does anyone else have any input?

Thank-you,
Christopher

Hi there,

Wish I knew someone had responded. Damn settings. Anyway, no you do not need to isolate the left/right and ground inputs. They are self isolated once the inter device such as the tape or CD player is inactive via the Stop/Play button or eject. Also, when wiring your relay, you might want to make sure that it at least keeps the power loop back separated from your audio inputs or you will get a buzz. The principal is extremely simple. Run your audio inputs, then run something to send power back to "T-On" to turn off the tuner (just like the CD or tape player does), and that's it.

Suggestion, try and keep it clean and simple. If you have an actual 3 piece unit, you can actually splice anywhere through the tape deck or CD player wires between the reciever/amp box and the device, but, do not cut the wires, just piggy back to them. Splitting between the wires is not needed unless you want to cut off the tape deck. If it is and AIO 3 piece unit, remove the reciever/tuner box, then, try removing the internal device plug by carefully unsnapping it from the side snaps holding it to the faceplate/controller head. Then you'll have access to each and every pin you need. Just take your input and switch wires and push them onto the back of each pin with a screwdriver directly behind the already existing internal device wires.

This can be used to add any device with line outputs by the way. All the stereo technically needs is line ins and a switch to send power back to it.

Well, I hope this helps a few of you,
Starflare5.

Hey,

Thanks for the reply. I've had this all set up and connected for about a month or so now. It works fantastic. The only thing I haven't been able to find is a normally closed 3.5 mm plug switch. The guys at Radio Shack looked at me like I was crazy. So, I've just been using a switch I mounted under the dash to switch to "Aux." input. Ipod works awesome with this system.

Thanks for the help for those that have posted.

Hi, I'm new to this forum, but I've been spending the last few days hacking my Delco stereo.

Like, lakata, I have a 1993 saturn with a Delco radio. I have successfully added a aux-input by hijacking the left/right signals from the radio board. However I have a correction to lakata's quote:

"found the left/right channel signals from the radio board (top board) to the control board. It is along the 8 wire ribbon cable. Unfortunately, I can't tell you which is pin "1", but the audio is on pins 5 and 6 counting from the back."

-lakata

On my radio, left is on pin 6 and right is on pin 7, counting from the back. (I have the radio/cassette version with the equalizer). I am using the radio chassis for ground. The sound quality is pretty good, since I am using the radio input instead of the cassette input. For now, I am using a switch to select between radio and aux input. Because I have tapped in right where the radio connects to the rest of the stereo, the balance and equalizer controls work for the aux input as well.

Hey guys! im new here. ok so i have a problem close to what you guys are talking about. i have a delco from a 91 buick regal gs. its plugs look something like the ones you have posted. but it actually has less wires comming out. me and a installer buddy spent a good 6 hours trying to get a input set. we are trying to use the radio as a amp (im putting some extra speakers into the car and didnt want to buy a expensive amp). so i dont want to use the tape deck. i want to use my aftermarket radio as a input into the amp so that it can power the other speakers. ill post up some pics when i get some but does anyone have any idea how this could be accomplished? thx alot cya!!

Here's some advice in using the stereo as an amp:

Internally, there are three basic parts:

The Radio
The Cassette Deck
The Amplifier (with EQ and other crap)

The amp input for the cassette deck will (i hear from others) sound like crap, because it's designed for tape, which has no high frequencies, and actually filters them out to reduce that 'tape hiss'

the radio input allows a lot more high frequencies since FM radio had more bandwidth than cassette tape.

You need to find the wires that run from the radio portion of the stereo to the amplifier portion. You will probably find that the radio is on a separate circuit board... the one the antenna plugs into. There will only be a few wires connecting it to the rest of the stereo.

Take a cheap pair of headphones (one you don't care about blowing up) and connect GND to the chassic ground of the stereo, and feel around with the other wire. do this with the radio on and playing a radio station. try to get the radio station playing on your headphones. once you do that you can find the Left and Right sound wires.

Then cut those wires, and feed in your audio input into there.

Once you have this new input set up, then you can think about installing a switch to let you re-enable the radio, OR you can do what I did and used an auto-switching stereo jack.

be careful, and good luck ! :-)