Ok, Look for:

1) Low voltage from battery when the key is turned to "on". What I mean is, measure the battery feed voltage at the ECM. Low-ish voltage at the ECM will cause a no-crank. I don't mean just measure the battery voltage under "ON" conditions, but measure rigth at the feeds to the ECM. Use the service manual to find what battery feeds there are, I believe their are two.

2) In manuals, you want to verify the clutch interlock switch.

3) I believe that, in autos, there is a park-neurtral switch, in fact, I know there is, I believe it's part of the SLA (Shift Lever Assembly). Verify it's operation.


Now, you can take the Pulse module out of the fuse box, pry the cover off, turn key to 'on', and manually close the relay (there are two, one for the SRT circulation pump, one for the starter). If closing this relay makes the starter engage, you know:
A) The starter/etc. is OK.
B) The issue is somewhere in the intricacies of the electronics between the starter contact on the ignition switch/the ECM/the Pulse module/etc.

If you have not done so, it is time to download the service manual and start tracing where your problem is.