Adding an AUX input to a Stock AM Radio

I have never found an aftermarket radio that I liked in a Corvair. They never fit correctly, unless the dash is modified, or just “dont look right”. I decided that AM wasn’t for me, and I didnt want to fork out the big bucks for a factory AM/FM Radio for my convertible. I already had an iPod, and thought it would be fantastic if I could connect it to my factory speaker, and use the stock radio’s volume control. Also, when the input is disconnected, the AM still works! This conversion works with both push-button, and manual tune radios.

In this article, I will describe the process of installing an auxiliary input jack onto a stock Corvair AM Radio. This is a pretty simple project, and will produce a pleasing result, if you are OK with MONO output from your device (still working on the stereo version). You will be able to connect any input device (Mp3, portable cassette, portable CD, etc) to the radio with a MALE – MALE stereo mini plug cord available at your favorite local electronics store.

You will need:

1/8” Male to 1/8” Male Audio Cable, length of your choice

1/8” phone jack, normally closed (should have 3 connection points)

1/8” Female to 1/8” Male Stereo to Mono Adaptor

Jumper Wire (24 gage)

First, the radio must be removed from the vehicle. For instructions, see the shop manual related to your specific model. Once removed from the vehicle, remove the top and bottom covers of the radio. Next, remove the front face of the radio. Be very careful not to disturb/ break off the pointer needle for the tuner. I found removing the face on the early model radio to be trickier then the late model, due to small pieces of the tuning mechanism. With the face removed, the volume control potentiometers should be visible. There are 2 on the volume control rod; the first is for the tone control, the second controls the volume. On all early and late model radios that I have seen, the AM signal input to the volume control is a light blue wire. This should be the farthest leg of the pot towards the center of the radio. The leg closest to the outside of the radio is the ground.

Typical Volume Control (rotated 90 degrees clockwise):

Ground Wire

Light Blue Wire

Picture of the Volume Control

Unsolder the light blue wire from the terminal. Solder a piece of jumper wire to this terminal, and also to the ground terminal. The pieces of jumper will need to be long enough to reach the location you wish to mount the input jack. Also solder (or use a solder-less connector) a jumper wire to the light blue AM signal wire that you removed. At this point, you are done working with the volume controls, so you may wish to put the front portion of the radio back together.

Connect the ground wire you attached to the volume control to the ground location on your input jack. The jumper wire that you soldered to the old input on the volume control goes to the connection on your jack that will contact the mini plug when its plugged in. The light blue wire coming from the AM circuit goes to the remaining connection on the jack. Without something plugged into the jack, the AM circuit should be complete, and the AM radio will function as normal. With the input device plugged in, it will play through the speaker, AND you can control the volume with the AM radio’s knob.

Next, find a suitable mounting location for the input jack. I mounted mine just to the left of the antenna input, on the bottom cover of the radio, for ease of disconnecting the input cable. I use the Stereo to Mono adaptor in the input jack, and then plug my stereo cable into that. I assembled a test station, with a spare speaker, and a 12V power source to verify proper operation before I reinstalled the radio into the car.

Testing the Radio

Once everything is buttoned back up, reinstall the radio into your car, and hit the road enjoying your new tunes. Good Luck!

Eric Prosise – Corvair Minnesota