5Series.net - Forums - New To Here (Alternator Issue)

I have a 2004 545i and I just had my alternator rebuilt, by a alternator repair shop that I trust and is known for their quality. Once I put it back on I got nothing, took it off and had them bech test it 14+v and 12+v under load. Put it back on NOTHING! Took it to advanced auto "good". Took it to a import repair shop that has all the BMW diagnostic equipment and they say its a bad alternator and the alternator has a communication problem. Was not convinced with their result.... Come to find out the small wire that has a plug is a switched positive and I was getting nothing out of it. Followed the little gray wire all the way into the box under the hepa-filter, no power. I have made a temporary fix by getting power from my lights but I want a real fix. Any thoughts?