Wednesday, March 6, 2013

Yet Another Original Car Radio Aux Input Mod

Yeah, bad title, get over it.


I got a new car because my 92' Taurus's ECM (the brain) decided to crap out. We decided it would be better to just get a new car. Oh, and this was in the middle of the interstate :D. Which meant that the motor suddenly stopped since nothing was controlling the motor electronics. Since i was going 70mph, it was quite easy to pull of to the side and think "what the hell" ?!?!?

I poked around craigslist and found one of the cars I've always wanted: a 1999 Mitsubishi Eclipse. This didn't work out because i'd know they were all owned by younger people and therefor shitily driven. Still wanting a Mitsubishi, i found a Lancer, but the same story. I settled on a 2002 Chevy Prizm for a good price. it doesn't have many features, but it gets 37 MPG. meh, it gets good mpg, "screw looks" i basically said. It actually had a CD player, so i didnt really mind no aux-in port. this soon changed.

While using it, i noticed the buttons were all extremely hard to push. Meh, whatever, i only need the main volume/power encoder, so i didn't really care. And then CDs stopped working. I'm screwed. I never listen to FM because i have no local Techno etc stations. i have ascended to the best music. So i took this radio apart, and surprise, surprise: pop all over the inside. It seem the previous owners spilled a bit. I started cleaning and soon realized that i couldn't do it by hand. So i walk over to the sink, fill it up with hot water and i wash my radio :D. FYI, it is the minerals in the water, not the H20 itself that fries electronics. Then i did a few rinse cycles in distilled water (pure H20), and dried it. The radio still works just as it did before the wash: no CD player.

Theory Stuff

I then began the same search as i did in my Taurus radio mod for the audio lines to the speaker amplifiers on the PCB and therefor bypassing the controls entirely and allowing a standard 3.5mm audio cable to be connected for aux-in. i was still unable to find the audio lines from the FM decoder to the mixer chip so i'm stuck without mixer controls on the radio (bass boost etc).

If your CD player still works and you just want aux out, then look at these sites: here and here. Note that the Prizm radio is essentially the same as the ones in those posts, so the mod works. i'd guess a lot of stock radios from the 2000's would have a similar layout and the mod would also work. This method allows you to still use the bass, treble and volume buttons etc on your radio with your aux device and the CD player still works when you take out the aux cable.

The Mod

Pull out the Radio

Use a screw driver to pry the black console frame off at the red line. Make sure you don't damage the dashboard foam/plastic stuff. Or you could some how pull out with some 90deg hook tool at the blue line. After you get a side loose, then just use your hands and follow the perimeter with your hands pulling out.

Pull the black casing off to the side to get the radio out. 

Take out the four yellow marked screws. Now, pull the radio out and up just over the shifter. Then, pull off the antenna connector and harness.  

Here's my radio before the mod.

Take off the mounting hardware and case

These plates are held on by a few small screws, and just pull off. Also, note that these are weird bolts, neither customary or metric sockets fit. I had to use a pliers.

These are the mounts for the radio to the car dash.One bracket per side. Three 8mm bolts each.

All the plates and brackets

Search for the magical mixer IC output lines

CD Player Mechanism below the top plate. 
This was simply puled out after the case screws were taken out.

The top PCB after taking out the CD player mechanism. Hot glued the cable to the PCB.

The bare PCB below bottom plate. Where ill find the input lines.

Labeled PCB

Mixer outputs to AMP.

Then i just soldered a 3.5mm audio cable to the pads, and soldered a ground.

1 comment:

  1. Great post with very useful information to all thanks for sharing with all of us
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