Hi Donny,
With Ron's meter it should come with a shorter cable that has a extra pigtail on it, right. This will connect to the GT control box, now on the other end the cable that come out of the S-1 Probe control box will connect to it and the coil cable will connect to the probe switching box. Now with the meter there should be a smaller wire that will plug into the meter on the front and the other end will plug into the pigtail of the short cable that is at the control box. Now turn on the meter as mine has a toggle switch on the back of it as it is powered by a 9 volt battery, next turn on your GT and check the meter for calibration with a new quarter or dime as it should read 179-180 and you are ready to go.
Most S-1 probe control box has a short cable so it has to be close to the GT control box unless you can find a extension cable and maybe Ralph at Sun Ray can make you one.
On the Sun Ray meter it was easier to do as the meter sat on top of the S-1 control box and the short cable from the switching box went to the meter and the meter had a longer cable to run to the control box for those that hip mount. Ron's meter is a great meter and very reasonable too, but gets the voltage signal from the pigtail on the short cable that runs between the GT control box and the S-1 switching box. If you were not using a S-1 probe it would be must easier to do as the coil cable would run right to the short cable with the pigtail on it and the small wire that Ron send with it that is longer would connect to the pigtail and then to the meter.
I hope I didn't confuse you more the way I explained it.
Rick