Here is your RPM vs. Amperage output chart.
The "S-Terminal" is the Sense terminal. This is nothing more than a voltage monitor that constantly measures the output of the voltage that the alternator is developing.
You should monitor the voltage downstream of the alternator and not at the source.
So, run that sense wire from the "S-Terminal" to the RED wire at position 12 on the bulkhead connector on the firewall. This is a good location to monitor the output voltage of the alternator, as this RED wire is the supply to the rest of the jeep and a voltage of 13.25Vdc to 13,85Vdc at this point will be ideal.
The bulkhead connector can be located at Grid D4, and the RED wire itself is at terminal 12 and identified as "12 Red 10 (6 & 8)" on the drawing.
The reason that your voltage is varying can be illustrated by observing the first link, where the voltage output of the CS144 alternator does not really start to crank out a steady or linear voltage until the RPM's reach 2000 to 3000 RPM's.
In addition, you have the Sense Terminal connected directly to the output of the alternator, so as soon as the alternator begins to output a charge, you are essentially telling it to stop outputing a charge... this coupled with the low RPM's of the engine result in varying non-regulated voltage control.
If you do not want to tie into the RED wire at this location, you can run the Sense wire to to the Starter Solenoid terminals where the positive battery terminal attaches.
Joe Guilbeau<br />1983 Cherokee Laredo WT (SJ-17), 360/229/727/D44/D60 4.10 Gearing, 8-lug hubs, Edelbrock Performer w/EGR Intake, Mallory Unilite Series 47 Photo-Optic Infrared Trigger Vacuum Distributor, Mallory Surge Protector, Mallory Promaster Coil, Holley Pro-Jection TBI 502-Analog, FlowKooler High Output Water Pump, Staggered 4-Core Custom Industrial Radiator, HD Fan Clutch, Dual Electric Fans, CS130 Delco 105-Amp Alternator, Oil Bypass Mods at Rear of Block and Distributor Oiling, Superlift 4\" Suspension, Rancho RS5000\'s, Hi-Tech 31\" Re-Treads, Aero 33 Gal Tank w/Skid Plate, Custom Rear \"Longhorn\" Bumper