Delco Electronics Radio Manual ((link)) Site

Before you search for a , you must decode the unit in your hand. Look for a metal sticker on the chassis or a barcode on the casing.

Without the , you would solder directly to the volume pot, which usually results in a loud "pop" when switching sources. With the manual, you can create a professional "Aux-in" that mutes the tuner automatically. delco electronics radio manual