by Bruce Murray
AONE Member

This document shows how I fitted a Pioneer 12 CD changer to my 164S. It's not the only way to do it, but it worked for me. My objectives were to minimize changes to the structure of the car and to avoid having to work in the under-dash area behind the radio. (It's a bit crowded in there and, if you can avoid it, so much the better). I also wanted to retain the factory radio rather than install a new radio that could control a CD changer. The easiest way to do this is to get a CD changer and an FM modulator that will play the CD music through the FM radio. Sure, it's not super high quality, but it's not bad and certainly no worse than regular FM radio quality.

The diagram shows the components in the Pioneer CDX-FM1257 kit that came from Crutchfield Inc. The main parts are the changer itself, the FM modulator, and the display unit. The modulator is called an "Antenna switching unit" in the diagram.

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I found it best to strip out all the trunk carpeting material to give maximum access to the car's wiring layout. The modulator is to be fitted in series with the car radio antenna cable, and although they recommend fitting the modulator close to the radio, it works fine when inserted in the lead at the antenna itself.

Two sources of 12V are need, one that remains on all the time and one that is switched on when you wish to play the CD system. Fortunately, having a power antenna at the rear of the car makes the hook-up very simple since it has both these voltage supplies at its connector. The uninterruptible 12V is on the Red-Black line and the switched voltage comes from the radio on the Yellow-Red line. The yellow-red line is hot when the radio is on. I was concerned that the current draw on the switched line might be excessive and cause problems for the radio, however the current draw is only a few milliamps and will do no harm.

I fitted the changer under the center of the rear parcel shelf in the trunk area. Pioneer supplies two brackets and suggests they be fitted as shown below. The problem with doing this on the 164 is that the holes for the bolts (E) would be inconveniently located.

It turns out that you can fit the brackets in reverse as shown in the photo below and this then allows the bolt holes to be inside the rear shelf lidded compartment .

To do this, you need to find 6mm or ¼" bolts with hex heights less than 3/16" so that they will clear the top of the changer case. Clamp the bolts with nuts to the brackets.

Drill four holes in the parcel shelf. Note that for the changer position I chose, two holes are very close to a stiffening shape. I used spacers cut to clear the stiffener:

This photo shows the inside of the rear shelf compartment (pity about the torn foam):

Here is the changer in place after the trunk interior carpets have been refitted:

After fitting the changer, wire up the power cables to the antenna area. At the antenna the uninterruptible 12V is on the Red-Black line and the switched voltage comes from the radio on the Yellow-Red line. The yellow-red line is hot when the radio is on. Note that these are the colors on the car wiring harness, the wire colors on the antenna itself may be different. I made up from an old harness a pair of connectors with short wires between them. These were inserted between the car harness and the antenna so as to avoid a direct splicing into the factory wiring.

Remove the rear seat back, seat base, and lower door opening trim. Peel back the carpet. Thread the display unit wire under the plastic channel and to the center of the car as shown in the dotted line:

Undo the two screws at the back of the console and pull back and lift it clear of the carpets. Feed the display unit cable under the center of the rear carpet and have its connector emerge near the rear console ashtray. For those who worry about running cable under carpet and the possibility of it getting damage, don't bother. ALFA have already been there before you - there is another wire there already, and a rubber pad to minimize abrasion.

Remove front ashtray and lighter from the console and feed the display unit wire through the ashtray opening. Run the wire back through inside the console - on the left side to avoid the parking brake- and have it emerge near the rear ashtray. Refit the console.

Cut a small plate from 1/8" thick gray PVC to fit inside the ashtray opening and make a cut-out in it to accept the display unit plastic surround. Glue the surround in place, fit the display unit, and snap the assembly into the ashtray opening. in plastic control box surround. The assembly will be held in place because of the springiness of the ashtray lid. I think it looks quite neat and if you ever need to take the system out, it is easy to do so and refit the original ashtray and lighter.

In summary, these notes are intended to supplement the maker's instructions and so I have not dwelt on all the details of wiring and system operation. On one final note, I did use level 4 for the modulation rather that the default setting of "3".   

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