I had a PD9200, and got the pendant. To be honest, I wouldn't bother getting one. Oh it's fun to play with at first, but the charger is smart enough that you can just let it do its own thing. No need to manually hit boost, even when using a generator for a fast charge. It will do what is needed.
I think functionally a 4600 is going to be the same as a 9200. The 4600 is just a retro-fit version.
I know you want the LED to work, because something is wrong if it doesn't. But first thing I would do is monitor the output voltage over a couple of days. Having a meter connected would make that much easier, and really handy to have at all times. Point being, if it isn't putting out correct voltages, the issue is deeper than just the wizard wiring.