When I bought the boat 8 years ago I dished out $800 for a new systems monitor DDU. Well a lightning EMP fried it a few weeks ago. I had no interest in another $800 purchase so I looked at alternatives. Since I have all mechanical engines with no Smartcraft and no Nmea2000, I went with the straightforward approach. I bought two $50 panels from Aqualarm. One for four bilge pumps and one for the four engine alarms I want (low oil and high temp on each engine). Here are the panels. They will be mounted side by side where the DDU was. Waiting on the engine panel to arrive. Here is the Systems Monitor schematic for my boat that I used for the wiring: Wiring the four bilge connections was straight forward. They go to +12v when active and the alarm panel triggers on sensing +12V. So I just cut the four wires off the connector and heat shrink butt connected them to a 16/4 cable that I chased to the bridge. The engine alarm requires a relay for each wire to convert a ground signal (the engine sensors go to ground when active) to a +12v signal for the alarm panel. Here is the schematic I am using for that. I am awaiting the panel and the relays to arrive so that’s a future installation. i am not connecting the generator or transmission signals. My generator is a replacement and the installer did not add the dedicated system monitor oil switch, so nothing to wire up. And my boat does not have transmission temp switches installed so nothing to wire up there. And I am not wiring the shower sump pump. No value in that in my opinion. I’ll post a final picture when I get the second panel installed.