I am trying to track down a short in my charging system that is not allowing the alt. to keep the battery fully charged. I have a new battery, Alternator and Voltage regulator and have had them tested -checked out fine.

I have the infamous "idiot light glow' problem and have decided it is most likely a short in a wire somewhere.

I have two possibilities:

1) radio installed is a recent aftermarket brand which the previous owner installed or had installed. I thought they had 'wired' it up so that you could turn it on even if the key was not in the ignition. Thinking that might be the culprit I pulled it out and it appears to be a standard install with only the power plug and speakers plug and antennae going into the back of the stereo -so I think this is ok. I was wondering if any other owners stereos are powered even with the ignition off.

2)The smaller red wire on the back of the alternator (not the ground or positive wire) doesnt seem to be cycling any current through it. (I used a testor) Is that smaller wire just for the in dash idiot light? If so it is comming on just fine... or could this be my problem?