How to Wire an ML320 Trainler Hitch Harness
 

I have already installed my hitch and my harness can be installed easily thanks to the information posted on this site. I bought a factory hitch and harness off of ebay as noted in another thread but the harness wires are loose at one end and not in the connector. There are several wires and four rows of connections. A1, A2, B1, and B2. Doens anyone know which wires go into which slot? You can kind of see it in this picture. It's the connection on the left with the tag attached.