You can replace just the 'main board' with a superior unit - while keeping the current WFCO 120V fuses, plastic case, cover, and 12V fuse board. panel. That saves a lot of time which you would otherwise spend in rewiring the 12V connections to a new fuse panel (i.e., 12V distribution board). It also ends up being a far better unit in many ways.
I was so unhappy with WFCO's failure to provide a proper "Bulk" Stage that I replaced the 12V mainboard, even though my original WFCO mainboard was still in "like-new" condition.
You can spend a bit more money than the cost of purchasing an entire new WFCO, and get the
vastly superior Progressive Dynamics mainboard upgrade (4600 series) instead. Or, you can spend about the same as a new WFCO and get the significantly better PowMax 'Boondocker' kit (Gen 4). I think that it's way better than WFCO, in both construction and charging logic, but not quite as good as the PD.
My install took only 45 minutes, and I'm not an especially handy person. You might need only 30. Replacing with another WFCO, DC fuse board and all, would probably take about an hour and 15 minutes. (Not 90 minutes, because you wouldn't have to do any re-cutting of the panel cut-out and the screw holes are already there.) But I think that keeping WFCO is a bad choice, I have been very unimpressed by the product performance.
Here's my own Thread on replacement with a 55 Watt Boondocker:
http://www.trailmanorowners.com/foru...d.php?t=14155.. All the replies are of value (read the whole thing, especially #12.)