The individual circuits with the drain can be determined by using the amp meter of a DVOM. Just remove the fuze (seems already done) and set the meter to its highest scale of the amp meter. Then plug/place the two leads directly into the position where the fuze came out. The circuit will have power and the amp meter will give you the reading of what is flowing through that one circuit. Try that, and we'll see what kind of power is flowing through that circuit. BTW, the radio circuit is powered "ON" so that you can listen to the radio even with the key off/out. All you have to do is push the power button. Of course the alarm circuit will be hot all the time for obvious reasons. Happy hunting!