Attached is a notional schematic. The LEDs are shown without resistors; this is simply because I may purchase panel-mount devices with internal current regulators, possibly bipolar.
LEDs 1-8 are red, indicating the corresponding fuse (1-8) is blown or missing.
LEDs 11-18 are green, indicating that the corresponding zone (1-8, in order) is active.
LEDs 19,20 are red or yellow, indicating the corresponding fuse (9 or 10, for zone Com1 or Com2 respectively is blown. (Yes, these could be merged, and probably should be LEDs 9 and 10 anyway.)
Fuses F1-F8 are 1A (ideally, about 0.5A), one for each solenoid.
Fuses F9, F10 are 2A (or as appropriate for your load configuration – the idea is that these would blow before the board fuse blows.
I’m going to give this a try with blade fuses; I found a block with 0.250″ tab terminals. I can crimp the indicators into the tab terminals; I’ll just need a mounting strip for panel-mount snap-in indicators, and relatively bright indicators if the ones I find are not bipolar.
