The BEST way to put AUX input on a '94 CD Player!
So, I decided to add an AUX input to a '94 Impala CD player. I discovered two things:
1. This is a easy radio to do this mod to, and it turns out GREAT!
2. The solutions I found on the internet were not very good.
Here is arguably the BEST way to add an AUX input to a '94 style CD Player:
Here's the view from the back.
Looking it over, you can see it is actually 2 halves. The lower half houses the CD player, the upper half is the radio receiver/amp.
After I removed three screws (one on the back, one on the top, and one on the side opposite the knobs), the top portion is easily removed, revealing a pair of plugs.
More importantly, I discovered something else-- The receiver/amp is the same as those used on an '88-94 truck! Here it is pictured with a unit from an early 90's truck.
This is good to know, as others have mentioned, Delco schematics are not made public. However, the receiver on the trucks is separate from the head unit, meaning that the pinouts for the unit are in the FSM:
So, here's what I did:
First, I obtained the following headphone jack, with isolated switch:
10 Pcs 3 5mm 1 8 Female Audio Connector DIP Stereo Headphone Jack PJ306BM US06 | eBay
Remove the large plug on the lower part of the unit by gently prying on the retainer.
Here is the plug.
Starting at the top, the first wire is the left channel coming from the CD, second one is right. Also, the bottom one is the switched power to the CD. These three are the ones you will be working with, so you might want to label them, as they are all brown.
Also, you'll be adding a line to the 6th pin from the top, which is the "Tape On" line.
You can remove the left, right, and 12 volt wires by gently working them out of the retainer, and then simply lifting it out of the clip.
installation of the wires to the jack are also easy, by sliding the wire below the tiny retaining clips, and then "punching them down" into the metal pin. It's best to use wire that is approximately the same size as the wires used in the unit from the factory. There is no need to strip them before punching them down into the plug, the little teeth will dig in to the wire pretty well.
Here is my chicken scratch schematic for wiring in the plug:
EDIT: The 3 wires leaving the jack (12V, Left, and Right) are the feeds to the CD player, that were removed from the plug.
Here is the plug, once I finished.
Once you're done with rewiring the plug, simply clip it back in place on the unit.
Mounting the jack, and how/where you want to mount it is up to you, I don't have any input on that, as I am mounting mine externally below the dash. So, I haven't looked into locations on where it might work on the face plate, or anything else.
How does it work?
First, the audio from your iPod will override the audio as you'd expect it to. The isolated switch in the jack also removes power from the CD player, stopping it in place, and at the same time, tells the receiver/amp that it is in "tape" mode, overriding any audio from the tuner.
Features/benefits:
1. Works like you would want it to, just plug it in, and it goes.
2. No additional switches needed, or CD's with a "looping track of silence" playing to make everything work right. <--Saw that in one solution I found on the internet.cwm3
3. CD player is still fully functional, disc will resume from the same place when iPod is disconnected from the AUX port, disc can be ejected while iPod is playing. Disc CANNOT be inserted though.
4. Can be done for less than $10.
Lastly, this should be able to be done the same way on an '88-'94 GM truck as well, only that the type of plug used on the receiver is different.
