A CCRM is kind of an expensive part to swap for trouble shooting purposes. If this were my car I would confirm the CCRM ground before replacing anything. The ground starts from the radiator core support and goes down around the battery and is a larger black wire with a white stripe. It connects to a round single pin connector. Make sure the connector is fully inserted and clean.
The same applies the the battery terminals and the ground connectors around the radiator core support.
Next perform a visual inspection of the CCRM connector. Look for evidence of overheating. Clean the connector with electrical contact cleaner and re-grease with di-electric grease.
IMO the odds do favor a bad CCRM but there is a possibility this could be:
- a bad ignition switch
- a problem with fuse F2.34
- a wiring fault affecting the CCRM pilot duty circuit.
If you want to rule out a problem in the pilot duty circuit get an "add a fuse" to create an easy way to monitor fuse F2.34 with a VOM or test light. What you are looking for is a voltage drop in the circuit when the problem occurs.
If the voltage drops suspect a problem with the electrical ignition switch. Note, the ignition switches do wear out and can be replaced by a DIY'er. It does NOT require PATS to be reprogrammed.
1999-2004 fuse panel schedule:
http://www.allfordmustangs.com/foru...r-swap-wont-fire-please-help.html#post2669271