As with all things that are electronic there is a methodical order to figuring out what is wrong with it, volts, ohms, and amps, come into play to help figure out what is wrong...
Volts = How hard the electrons are being pushed through the wire.
Ohms = How much resistance is in the wire/circuit that the electrons encounter while trying to get from positive to ground.
Amps = How fast the electrons are moving through the circuit.
The first question is the age old question "Is it plugged in?", so...
Is is plugged in, and is it plugged in all the way? Another way to put this is check all of your wiring for something that is obviously wrong that would keep the circuit from working, loose plugs, burnt plugs, wires that have been pulled out of plugs, wires that have frayed and broken off, etc.
Next is... are there fuses, and if so are they blown? Even if they look "ok" test them with an ohm meter they should be 1 ohm or less, if they are more than 1 ohm replace it.
If everything looks ok put the multimeter on "Volts" and test the positive wires to your coils, you should be getting something around 12 volts with the engine off, if you are not getting 12 volts you need to back track the wire(s) until you can find 12 volts again, and once you do your problem is in between those two points, don't use the frame as a ground for the negative lead of your multimeter connect it directly to the negative post on the battery.
Considering that you are getting 12 volts then it is time to check your ground, put the meter on "Continuity" and put it on the ground wire you should get 1 ohm or less if this is a "brain box" and not an actual ignition coil, if it is an actual ignition coil this test may not work.
If this is an actual ignition coil do a continuity test from the coil's NEG terminal to where ever the wire ends up, again it should be 1 ohm or less.
If the wiring all seems to be fine disconnect the coil and do an OHMS test across the positive and ground wires, if you get nothing (infinity) or only 1 or 2 ohms your brain box is probably fried.
Considering that the coils are getting 12 volts and the ground wire is ok you can also put a DC "amp clamp" around the positive wire and it will show how many amps are going through the circuit, you would need to run some "Ohms Law" calculations to figure out the actual number but if the amp clamp is showing "0.0xx" amps then the "load" in this circuit is dead (i.e. your coil/coils), with the point being if there are no amps present then the electrons are not going anywhere to make the circuit work.
I hope this was helpful and not too confusing.
