Did you have your batteries checked? I had two yellow tops go bad after 2 years on my kit (using benchmark also,) but I think it was the batteries and not necessarily the kit at fault.
I also sent Benchmark emails, phone messages, and PM's. Got a response a few weeks later, but they we're really not much help and stopped responding after I sent them pics and info on what I had and defined my problem.
I have the K.I.S.S dual battery system, their first generation that they have since changed.
I am still running the wiring the original way since I haven't had any problems, but I did get their revised wiring kit and instructions. If that's what you need, I can send a scan of the instructions your way, drop me a PM with your email address.