HI brad,
Yes, you can use it to do the ballast too. There's a second decc for ballast controls, and they switch another box with four large relays that do the two pumps and two valve (factory SX ballast)
I decided to get rid of the 2nd problematic DECC and retain the other relay box with the four relays as it does the level display for the ballast tanks and I want to keep that. So, you can take the four orange wires off the second decc and wire it right to the new relay box. I am trying to decide how to place the buttons on the screen, but as far as function goes its no big deal and the new switchpanel will control everything.
One thing that is very important when using relays to switch inductive loads (motors, pumps, fans, blowers) is that you need a suppressor diode across the load or it will not switch properly or consistently. Toyota mentions this and I think you can order them from the parts page, I simply make them using 1n4007 diodes and will include a bunch with any unit I sell. they call them suppressor diodes.
Our boats needed these and boat dealers did not know this when wiring accessories. There is a voltage spike that happens when the load is switched off (magnetic field collapsing causing a surge) and this spike probably kills the microprocessors in the DECC system over time. I think it is a big reason for the decc boxes and button panels failing.
Brad, I'll send you a PM with my number if you don't have it, you have been very helpful over the years and I will cut you a break. System comes with a manual and technical assistance, it's designed to be plug and play so it shouldn't be too hard for you to install.
