Spektrum AR9020 binding please help!

Alright this one has me going nutty. And it's s fairly simple problem. I just picked up a DX18 remote and an AR9020 to use on a hydraulic excavator. I'm trying to bind them together but not having any luck bi know this is an extremely simple task to accomplish which I've successfully done many times. When I plug the bind plug in and apply power to the receiver (using a 6.6v receiver battery) the orange led on the receiver does nothing! I've tried this on 2 other AR 9020s with the same results. What gets me is I have a AR9000 receiver and when I try that it works fine! What am I missing here?!?!