azsailor12, I do have one question that you may be able to comment on if not too much trouble.
I have a control box from an old Norcold SCQT-6407 which is a predecessor to the 4407/4408 systems. It has a knob to adjust the temp, an ON/OFF slide switch, and one LED - pretty simple. I was hoping it would be compatible, but it has 4 wires into a plug
, whereas the one for my 4407 needs 5 wires. I hope to learn why the newer 4407/4408 systems needed the additional wire.
My question is whether your control box has anything more than a knob, switch and LED?
Also, if anyone has a dead 4407/4408, I am in the market for a used control box, as well as a set of male and female quick-connects.