(There has got to be a better way!!!)
One of the posts regarding the tape deck auxillary input modification mentions routing the input through the IR sensor. Don't have a remote? Don't need it. Make better use of the space. Also, another post or two had mentioned cutting out a ridiculous amount of bass. There was mention of resistors... I chose capacitors. I'm not sure if it was suggested somewhere or my military electronics training actually kicked in. The caps act as a high pass filter. This is passively the most effective way to do this.
Additional supplies:
(2) capacitors, best electrolytic, 0.1->100 uf (micro farad, seems to be ideal). I believe mine were 0.17uf
(1) low profile/panel mount 3.5mm audio jack, stereo.
Wire, 22 gauge is ideal. I used 18, stronger yet harder to work with.
All of these items from a local Radio Shack... I have luck with RatShack, most of the time. Want some really decent parts? I'd still say RatShack will work, just use the online site and buy NTE caps, and if you can find it, it'll be elsewhere, a SwitchCraft jack. Whatever you choose to use in your project.
If you use the Radio Shack parts, this mod is under $10, assuming there is some wire lying around.
This post helps a lot with the inital disassembling, soldering and general purpose of this modification:
https://www.matthewsvolvosite.com/forums ... 33&t=53690
Solder the caps to the R ch and L ch, to the board if you can. If not, I'd recommend using and electrolytic cap and a wire lead, easier to solder into the printed circuit board. My usual trip to RatShack ended up using polyester film caps, somewhere in the 0.1 micro farad range. Increasing the capacitance a slight bit (roughly a 1000 uf cap would be quite small yet more effective)... Also, from my car audio days of my youth, electrolytic caps are what I used for regulating current and high pass filtering. The caps I used still have a greater volume than say, the radio, or tape adapter with variable volume (my CD player stopped working, it's a dead media to me anyway). The main problem with the insane amount of speaker-killing bass is not an issue anymore.
Disassembling the face is delicate. Remove volume knob. I recommend using a few different flat head screwdrivers, at least three make the process faster and painless. Once the face is disassembled, remove the three equalizer slider knobs. Using a trim puller or bone tool is ideal. Don't use a flathead screwdriver. I did. In my case it added character to the radio plastic wearing. Using a small philips head driver, remove every screw holding the face plate circuit board. Separate board from face plate.
Remove IR sensor cover (just break it out... might not want to re-use it) and de-solder sensor from the circuit board. It is designed to work without it. I ripped mine out and was quite successful. You'll want to do this so that the radio face plate is painless to reassemble.
Cut out a spot in the existing IR sensor hole for a 3.5mm jack. Install went pretty well, aside from bending and breaking some terminals for ease of installation and soldering directly to the cable contacts. My ground lug was the only lug left, bent parallel to the jack body. Fits great. Personally used an x-acto and some wood carving knives to achieve a clean mounting point. I used superglue to hold it in place. After the first jack snapped (this is why I suggest ripping the IR sensor out), I was a bit overzealous with the glue. Again, character. Whatever you feel comfortable using, the plastic material is pretty easy to work with using a good, sharp x-acto.
Remember:
Tip: end of 3.5mm plug. White wire (as in RCA connectors), Left channel.
Ring: middle contact of 3.5mm plug. Red wire, Right channel.
Sleeve: bottom contact of 3.5mm plug. Black wire, common ground.
Route wiring as shown through out to the side of the faceplate and through the opening in the board. Pull gently to remove slack for reassembly.
Solder to the pre-amp channel points as shown in the cross-referenced forum. My pic was a bit messy yet used the same solder points.
Reassemble.
- Finished and functional. DIY smartphone mount mod (via LifeHacker) below, clipped to center console. Binder clip, rubber band and yarn. Best mount ever!