That's true and if he had a scope available you can see them working in real time but seeing as he didn't mention the pattern he was getting I assume he doesn't so that leaves the mechanic on a forum with a bit of a dilemma.
Did the coil that cracked at 65K go defective or did the failed module do the dirty deed? We don't know, we will never see the parts on the engine to determine what happened.
If he changed the cracked coil and it started right up I would say run it and worry about the others when/if they fail but that's not the case, the module got taken out so whatever happened took more than one component out at the same time. IMO its prudent given the cost of this module and the coil he already changed to go ahead and spent the price of 2 coils rather than risk the possibility one of the ones installed when this happened didn't suffer some internal damage.
I never throw parts at anything but when caught like this where I cant see it or diagnose it with equipment I rather be safe than sorry, its the lesser of two evils.
Did the coil that cracked at 65K go defective or did the failed module do the dirty deed? We don't know, we will never see the parts on the engine to determine what happened.
If he changed the cracked coil and it started right up I would say run it and worry about the others when/if they fail but that's not the case, the module got taken out so whatever happened took more than one component out at the same time. IMO its prudent given the cost of this module and the coil he already changed to go ahead and spent the price of 2 coils rather than risk the possibility one of the ones installed when this happened didn't suffer some internal damage.
I never throw parts at anything but when caught like this where I cant see it or diagnose it with equipment I rather be safe than sorry, its the lesser of two evils.