Water pump and electronic ignition
There are diagrams floating around on how to wire the light into the circuit so it comes on when the water pump loses power (fuse blows) or loses ground connection. Basically whenever the pump is not energized.
You will need to become familiar with 12V car relays in order to do this. My Meziere was supplied with a inline 30A relay along with a inline fuse. This allows you to "trigger" the relay via a switched ignition wire (anything that is ONLY "on" when key is in KOEO/KOER position") which is how they tell you to wire it. When relay is triggered, it allows full current/power from battery circuit. I have my WP turning on when my fuel pump is energized..basically when I click my key over to "auxiliary" position it will turn on.
The light is a further step using the same relay but "opposite" how you wired the WP. This relay is always energized (when in KOEO/KOER) by the power going to the WP. If this relay loses power to it, which means the WP lost power, the warning light will light up.
If your weak spot is understanding wiring schematic then maybe you can ask someone you know that may understand it. Or have someone that knows wiring/mechanical aspects to do it for you.
I have a mechanical engineering degree, even though there are plenty of wiring schematics online showing how to do it they can still be confusing as to why someone did it the way they did. I did mine combining a couple different setups.
I can only suggest doing some research about wiring and use this as a learning process to broaden your automotive abilities.

