Yet another no spark

[Xs924S]

Working on my son's 87 924S.
BLUF: current no start may be due to 9.6V at coil not 12?

So far we have:

Changed out timing belt and balance shaft belt and pulleys.
changed out the sensors and got a spark with starter fluid spray.
Then worked on the fuel, changed the tank screen (not as easy as everyone makes it out to be), changed the fuel pump and filter, cleaned and rebuilt the injectors. tested injectors attached to fuel rail and all are spraying when the car is turning over.

Now no more spark... bad coil so so we bought an MSD Blaster 2 coil, put on a new dizzy cap, gaskets and button, new wires, no spark between new distributor cap and plugs. 9.6V at both terminals when ignition is on.

What we are seeing:
coil is within spec
spark plug at the end of coil wire will spark once when cranking
9.6 v from both + and - coil terminals -this should be over 12 since that is what the battery is reading

We have not taken out the DME yet, or the relay since we are getting voltage to the injectors and coil.

Any insights would be great!

Thanks

[944 Ecology]

Here is a tried and true ignition troubleshooting guide, works a lot better than the parts cannon:

Ignition System Troubleshooting

[Xs924S]

Thanks, that has been our bible, amazing amount of information. Just don't have a spare DME so hoping someone has seen this condition before, and may know if a specific solder joint in the DME will fix it.

[Xs924S]

Problem solved. Some PO put an aftermarket alarm in, I do not think it ran since then... I cut everything out and when tracing the ignition wires, found a hard ground spliced into the green wire by the front right. Cut it and voila 12 v to the coil and it started right up.

[Fast Freddy 944]

I'll be dammed, thars yer problem. Yeup folks that drive Porsche and sports cars need alarms, so.....

[Xs924S]

It was very secure, no one could ever start it!

[944 Ecology]

Yep, I'm pretty sure that none of us in the internet world was going to figure that one out for you.