Stock Head Unit Aux In?
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Here's something I have done before, with good results. Does it have a cassette player? You have to be good at soldering really small wires, though. If you think you can do this without ruining the radio (From static discharge), read on. Ok, inside the cassette playing mechanism is a read head. It's the thing that reads the change in magnetic field on the tape inside the cassette and sends the weak signal to be amplified inside the radio, then sent to the speakers. If you feel comfortable taking your HU apart, you will see that the head probably has 3 wires, a ground, a left channel read, and a right channel read. The ground typically is a shield, and the other two wires may be red and white, or red and black. What you need to do is trace these wires back to the PCB (Printed Circuit Board), and solder on your own wires that piggy back the read head wires. Shielded wires are preferable. You can purchase a decent quality rca- rca jack, cut the one end of rca jacks off, and drill a hole in the HU for the rca jack (You might not have to do this, if you can find space to route the rca wires outside). Once you have traced the wires back to the PCB, strip the wires for the RCA cord you bought, and join the two shielded wires together, and strip the red and white wires. All that is needed now is for you to solder these wires to the pcb where the read head is soldered. Shield- shield, red- red, white- black or white- white. Now, if you have a cassette deck that automatically goes to the other wide of the tape, to hear the auxillary, you have to switch yoru head unit to cassette (With no cassette in it!), and you may have to tell it to read the other side of the tape before your auxillary input is activated. There is also another complication that is possible, and that is certain decks sense when only one of the drive rotors is spinning (I.e. when the tape has ended, or when there is no tape in the deck) and they will switch to side B, back and forth from a to b. There is a way to disable this, but it's even more complicated (You cut the power to the drive motor, and wire it to a remote switch). Another thing to know is that the read head is very sensitive, the incoming signal must be pretty low, or it will distort. Like I said, I have done this a few times with good success, even making a small guitar amplifier out of a microcassette recorder once.
It's even easier to do if there is an external tape player, because you don't have to take the radio apart. I am not aware of any adapters that are made that will allow you to have an aux input. You need a pinout of the connector. So do you have the cassette player externally mounted like in my truck, or is it just an option? The easiest way to find what pin does what is to use some sort of audio signal source (Like a walkman with the 1/8" jack to spliced wires) and try each wire individually until you hear audio in your speakers. The problem is you will eventually hit 12v which will blow your walkman up, which is why you need a multimeter to test each wire for the presence of 12v, and avoid those wires in the audio test phase. What needs to be done, is to ground out the output from the walkman, and use the splied wire to touch the non voltage present wires to see if you get a sound. Eventually you will hear output on the left side, then the right side. Note these wires. Finding the audio ground might be as simple as just grounding to the chassis of the cassette player, or a black wire. This is something that may take you 2 hours to do, or less if you are experienced with electrical tweaking. The easiest option might be touching the spliced wire output from the walkman directly to the cassette input on the radio, as you don't have to strip any wires. Of course check the pinout on the radio for the presence of any voltage higher than 1 volt, I am guessing, because it poses a risk to your walkman. Not including taking the radio out, checking the voltages and checking for audio input shoudl not take more than 15 minutes. Write down your results so you don't have to do it again. Once you find the wires that are responsible for relaying audio the the HU, all that is neccesary at that point is to strip a small amount of insulation from the wire in the harness, and soldering the appropriate wire from the rca connector to it. There is a remote possibility that you may have 4 audio output wires, one for each track on both sides of the tape going to the radio, but that is not likely. Give me a second to look at my radio and I will tell you if I find anything of use to you. This sounds complicated, but it really isn't, compared to rocket science. Just kidding!
I have good news for you, sir!
And bad news as well!
Upon opening my cassette player, I determined there is a single connector inside that is responsible for the audio output from the tape head.
IF you are looking at the connector on the tape unit, assuming the locking piece of the connector is facing BOTTOM, the pin to the left we will call pin #1. There are 9 pins total. Pin 1 is a power pin, going to a diode. Pins 2 and 3 also look like power pins, but they could be anything, however, they are not relevant in this situation. Pins 3, 4, and 5 are the audio output pins.
3: Blue wire. Consider this the 'ground'.
4. White wire. Consider this the 'left' side output.
5. Red wire. Consider this the 'right' side output.
To verify these results for you, I whipped out my HP 3311A function generator and pumped a 1.5Khz signal into each pin. The above pinouts are correct.
To connect to an RCA cable: Solder the ground portion (Each side ground connected together) to pin 3. Solder the white or left hand side input to pin 4. Solder the red or right side input to pin 5. Again, this is assuming you have the cassette mechanism harness adapter so that it's locking mechansim is facing DOWN, and the first pin is on the LEFT.
Now the bad news!
On my radio, when a cassette is removed, it automatically switches over to the CD player function. In other words, you have to trick the cassette player into thinking there is a cassette in the unit. This is most easily solved by putting in a cleaning cassette that will output no audio, or one of those cassette tapes that has the cord sticking out for a cd player input. Something that will trick the cassette player into thinking there is a cassette inside.
Now if you do not have a cassette player, you may be in for some bad news. You either have to obtain one (They are available, check the local junkyard, and there are some online resources (My cassette deck is model 16210495), or rig a pretty sophisicated device to fool the radio into thinking it has a cassette player. This is all assuming you have the same type of Delco radio that I have too, so these findings may not even apply at all!
And bad news as well!
Upon opening my cassette player, I determined there is a single connector inside that is responsible for the audio output from the tape head.
IF you are looking at the connector on the tape unit, assuming the locking piece of the connector is facing BOTTOM, the pin to the left we will call pin #1. There are 9 pins total. Pin 1 is a power pin, going to a diode. Pins 2 and 3 also look like power pins, but they could be anything, however, they are not relevant in this situation. Pins 3, 4, and 5 are the audio output pins.
3: Blue wire. Consider this the 'ground'.
4. White wire. Consider this the 'left' side output.
5. Red wire. Consider this the 'right' side output.
To verify these results for you, I whipped out my HP 3311A function generator and pumped a 1.5Khz signal into each pin. The above pinouts are correct.
To connect to an RCA cable: Solder the ground portion (Each side ground connected together) to pin 3. Solder the white or left hand side input to pin 4. Solder the red or right side input to pin 5. Again, this is assuming you have the cassette mechanism harness adapter so that it's locking mechansim is facing DOWN, and the first pin is on the LEFT.
Now the bad news!
On my radio, when a cassette is removed, it automatically switches over to the CD player function. In other words, you have to trick the cassette player into thinking there is a cassette in the unit. This is most easily solved by putting in a cleaning cassette that will output no audio, or one of those cassette tapes that has the cord sticking out for a cd player input. Something that will trick the cassette player into thinking there is a cassette inside.
Now if you do not have a cassette player, you may be in for some bad news. You either have to obtain one (They are available, check the local junkyard, and there are some online resources (My cassette deck is model 16210495), or rig a pretty sophisicated device to fool the radio into thinking it has a cassette player. This is all assuming you have the same type of Delco radio that I have too, so these findings may not even apply at all!
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3067210804&category=48612
Her is an ebay item for that cassette deck. Some things you need to consider. If you purchase the cassette deck, you also need the wiring harness. You will also need the change tray with the cutout for the cassette deck. The connector that interfaces with the HU from the cassette deck is on the lower left portion of the HU. The right hand harness is for the speaker outputs, lights, power, etc to the HU.
If indeed you do go through all this BS, the auxillary inputs will be as high quality as any inputs on any HU. The quality of the tapes you hear is due to the poor interface of magnetic tape versus the unadulterated sound you hear via a compact disc, which is pure digital, and doesn't suffer any signal loss. This is virtually the only way I know of that will allow you to have auxilliary inputs on a Delco radio. I know, :twiggss:
Oh nevermind, he includes the wiring harness. All you would need is the change tray cutout.
If you do end up purchasing the cassette deck, remember, on top of having the AUX inputs, you will also have a cassette deck that functions, too!
Her is an ebay item for that cassette deck. Some things you need to consider. If you purchase the cassette deck, you also need the wiring harness. You will also need the change tray with the cutout for the cassette deck. The connector that interfaces with the HU from the cassette deck is on the lower left portion of the HU. The right hand harness is for the speaker outputs, lights, power, etc to the HU.
If indeed you do go through all this BS, the auxillary inputs will be as high quality as any inputs on any HU. The quality of the tapes you hear is due to the poor interface of magnetic tape versus the unadulterated sound you hear via a compact disc, which is pure digital, and doesn't suffer any signal loss. This is virtually the only way I know of that will allow you to have auxilliary inputs on a Delco radio. I know, :twiggss:
Oh nevermind, he includes the wiring harness. All you would need is the change tray cutout.
If you do end up purchasing the cassette deck, remember, on top of having the AUX inputs, you will also have a cassette deck that functions, too!
wolfmangk: I cannot thank you enough for all the reserach you have done and provided to me. After reading all you have said, I think the best thing I should do is just to get a new head unit. I'd like a CD player that can play MP3 CDs anyway, and I've got some extra cash from Christmas.
A few questions come to mind. Let's say I get an Alpine CDA-9813 (a friend suggested this), how will this hook into my current speakers. Futhermore, most units on the market are 1U units, while my stock headunit is 2U. What's going to fill in the extra gap, and how will the radio fit into a hole that's bigger then it is?
-ee99ee
A few questions come to mind. Let's say I get an Alpine CDA-9813 (a friend suggested this), how will this hook into my current speakers. Futhermore, most units on the market are 1U units, while my stock headunit is 2U. What's going to fill in the extra gap, and how will the radio fit into a hole that's bigger then it is?
-ee99ee
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21,222 Posts
ee-
The 9813 is a great deck. You will like it.
You will need to buy a dash kit (Metra 99-3300) and cut the inner piece out, a GM wiring harness you can buy @ Sears or Walmart, and a GM antenna adapter.
The GM harness goes from stock harness and then splices into the wires coming out the back of the headunit. You will need a wiring diagram for which wires are which. http://www.installdr.com/QuickWiring.html and then GM/Saturn
The deck will sit in the middle of the dash kit, and the dash kit will fill the gaps.
The 9813 is a great deck. You will like it.
You will need to buy a dash kit (Metra 99-3300) and cut the inner piece out, a GM wiring harness you can buy @ Sears or Walmart, and a GM antenna adapter.
The GM harness goes from stock harness and then splices into the wires coming out the back of the headunit. You will need a wiring diagram for which wires are which. http://www.installdr.com/QuickWiring.html and then GM/Saturn
The deck will sit in the middle of the dash kit, and the dash kit will fill the gaps.
ee99ee, you hurt me in my heartee99ee said:
Just kidding. I hope someone, somewhere, sometimes uses this info to their advantage. I might get XM or Sirius someday, and it's good to know exactly what does what. Hey, I was going to do this stuff anyway, better to have it out of the way, eh?
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