Couple of weeks back I picked up a late 70's Philips radio for my Mk1 Golf GTi, i've seen a few companies that offer to conversions to allow these radios to also function as an mp3 player. The electronics in these are pretty basic, all you need is a 3.5mm normally closed jack to allow the radio to function as a radio with no lead plugged in, and automatically switches to the aux mp3 input when a lead is plugged in. You'll also need a resistor with a resistance between 80-200 ohms, some wires, a multimeter and a soldering iron.
This is the aux jack, I bought mine off eBay for £1.79
5 pin outs
Quick diagram I made up, obviously the wire colours can be whatever you wish, I used some 22awg that I had spare.
To make wiring in the radio simpler, I soldered a 100 ohm to the end of the yellow source wire and then soldered that to the green wire running to the source wire on the potentiometer.
The potentiometer controls the on/off, volume and tone on this radio there are 3 pins, one is the source, the middle is for the volume control and the third is the ground.
The three vertical pins on the top left are for the potentiometer. Using the multimeter I found the lowest pin to be the ground wire. The middle is always for the volume control so by elimination the top pin was the source.
What needs to be done is the wire running to the source needs to be disconnected (use a sharp knife or screwdriver to break the copper wire on the motherboard). PIN 3 (white/black wire) needs to be soldered on the tuner side of this broken connection, and pins 2 and 5 need to be soldered onto the potentiometer side of the broken connection. The earth should be soldered to the earth (obviously!).
Make sure everything works, with the lead plugged into the jack the mp3 should play, unplugged it should automatically switch back to the radio. Once you are happy, clean everything up, make sure your wiring is nice and neat, and install!
This is the aux jack, I bought mine off eBay for £1.79
5 pin outs
Quick diagram I made up, obviously the wire colours can be whatever you wish, I used some 22awg that I had spare.
To make wiring in the radio simpler, I soldered a 100 ohm to the end of the yellow source wire and then soldered that to the green wire running to the source wire on the potentiometer.
The potentiometer controls the on/off, volume and tone on this radio there are 3 pins, one is the source, the middle is for the volume control and the third is the ground.
The three vertical pins on the top left are for the potentiometer. Using the multimeter I found the lowest pin to be the ground wire. The middle is always for the volume control so by elimination the top pin was the source.
What needs to be done is the wire running to the source needs to be disconnected (use a sharp knife or screwdriver to break the copper wire on the motherboard). PIN 3 (white/black wire) needs to be soldered on the tuner side of this broken connection, and pins 2 and 5 need to be soldered onto the potentiometer side of the broken connection. The earth should be soldered to the earth (obviously!).
Make sure everything works, with the lead plugged into the jack the mp3 should play, unplugged it should automatically switch back to the radio. Once you are happy, clean everything up, make sure your wiring is nice and neat, and install!
