Thunderbolt IV no spark, at my wits end

[nitrous_bob]

Ok I've run through the flowchart, about 10 times. With the key on, I have 11.8V on both sides of the coil. The batteries are at 12.4V
The red/white from the coil shows 10.6V
I replaced the coil and ignition sensor anyways.
I used another module that is "supposedly" good from a running motor
The only part of the flowchart test I'm unsure of is where you use a spark gap tester on the coil and unplug the green/wht wife from diz and rapidly strike it to ground.
Wouldn't it be the same thing with a wire from coil to ground ? Or for that matter a lead from the green/wht wire right to the coil tower ? I'm no electrician but I can trace wires and follow directions. I still have no spark from the coil when it turns over. The only variables I see , is that the module I tried is no good, or I'm totally lost trying to spark the green and white wire. Help me out please.
The boat was running for over an hour, stalled.... Now no spark

 

[Fun Times]

Hi there, welcome to iboats!

For starters, What do the other red 12v powers wires on the engine read such as the circuit breaker? Closer to 12.4 volts?

Does the voltage seem to change at the coil while the engine is cranking over?

 

[Bt Doctur]

Try this. the module mounted to the riser has 4 wires. 2 go to the dist and 2 go to the coil (purple and grey) , the engine harness has the same 2 colors but purple is the 12V and grey is the tach lead. .Disconnect both and run a wire from the + battery to the + side of the coil(where the purple wire goes) and report if it now runs

 

[nitrous_bob]

Other power wires are 12 volts yes

While cranking , both sides of the coil drop to about 9.25v

I tried removing the harness wires too, and powering the coil with a lead from the battery.

Still no spark from coil

 

[alldodge]

Howdy

Here is the TB-IV troubleshooting flow chart

 

[cobburn]

The part you are confused about (touching coil ground against negative) is thats how spark is made; rather when then ground or the is broken and applied again the stored energy in the coil (a coil is a transfomer hence it's primary and secondary windings) then jumps the spark plug gap as the plug is screwed into the head which is ground. So with that test you are emulating what the ignition module does to create spark. so hook your spark tester to the coil and ground it then put 12v to it's positive and run a wire from it's negative terminal to negative and touch and untouch it rhythmically. you said you have a gap style tester and so the spark should be able to jump 7/16 to 1/2 an inch as well as be nice and blueish white. you can check the resistance in the coil as well (forget exactly what both are off the top of my head but not hard to find)

 

[figaro]

is the distributor /rotor even spinning when you crank her over ?