... If the CS does not have a sensing wire then I wont use it. A one wire alternator may charge the battery, but an alternator is more than a battery charger.
The CS does have a sensing wire (it's "S") - but it's just not necessary to wire to remote storage source (battery) for most installations
confuse an Internal Sensing
alternator (like the SI/CS series) with the junky Self-Exciting
Aftermarket "One-wire" POS's sold by retailers
Those are totally different devices.
The remote sensing part of the CS unit is to "look" at the reference voltage at the the remote storage (battery) location and make sure it is getting enough voltage to charge correctly. On installations like a boat, where the battery is more than 10 feet (in my case) from the alternator, the voltage drop through things like the battery sellector and wiring can be enough to drop the voltage below the 14.5~14.7vdc necessary to effectively charge the battery(ies).
If you want to wire it to sense from somewhere like the main power source it's easy;
Wire the "S" terminal to the "Bat" lug on the battery itself or your main power-lug/tap, wire the lamp circuit with a diode (to prevent forward voltage to the alternator) to the "F" terminal and then wire the key-on source to the "L" terminal - this will give you full voltage sensing and adjustment based off the voltage main storage/distribution circuit(s).
Wiring the unit so the lamp and 12vdc source goes to the "L" wire and the "S" terminal to the "Bat" terminal with a jumper allows the alternator to "sense" the voltage in the short #4 wire, usually found on our cars, between the alternator and the battery - it will not appreciately drop in that short piece of large wire ...
This is by far the easiest way to upgrade most car systems.
I've done bunches of these in upgrading systems for friends and they work great with no 'sensing' issues.
Hopes this explains it better and you can feel better about the wiring options.