Hi Rev
I agree that removing it is the best answer, an unreliable alarm is a PITA.
Insofar as the issue with it killing the spark you need to determine :
- is it just killing the spark or is the entire ignition circuit dead ?
If just the spark head to the coil and track the wires, there should only be a couple, Dizzy, condenser, suppressor & power supply.
If everything is dead, then you need to look at the ignition circuits under the dash.
It is really hard to diagnose via email, but hopefully this will give you a start (no pun intended)
Anybody local to Dave able to drop past ?
Cheers
PB