Timing light on DIS?

Can a timing light be hooked up to the DIS on 2000+ Cherokees? It would be a bit tricky without plug wires to work with, and I understand that I can't really adjust ignition timing. I really need to see when I'm getting spark in relation to the crank.
I tried hooking up an inline tester to #1 plug boot, grounding coil rail, and putting the pickup of a timing light on the lead for the inline tester. The timing light did not pick up a signal, or at least it wasn't flashing at all.

To answer your question -NO-.
Go buy a scan tool. Like a Snap -on 2500 or better, plug into the OBD port and read the info in real time. The PCM controls all aspects of the ignition. Plus the plugs fire 2 times on each stroke,one is wasted...

I have a 2500, but I don't have the updates past 1998. Was hoping to find a way to hook it up with what I've got here.