From a signal integrity/attenuation standpoint, I would seriously advise against using crimps on any sensor. Any output that's not ignition or injection could be crimped. When using male-female crimps, I always solder the wire to the terminal after smashing it. For the larger wires, it just takes a long time with the soldering iron. I have an adjustable one that I crank up to 800*F and use a large tip with, and it still takes a while. I wouldn't crimp the alternator wire. The main problem with crimps on an automotive installation is the inevitable vibration it will have to endure. It is only a matter of time before the connection will fail.