deg15scorpio, you cannot test the short circuit current through a 100 Ohm resistor. The resistor will limit the current according to Ohm's law. What I have done to sort cells, although probably not the best, is to solder the front and back tabs on and to measure the current with a meter while aiming the cell unobstructed at the sun at about noon on a sunny day.
In the past if I did not have a meter capable of making an accurate measurement, I would have found a 1 percent tolerance resistor of about a tenth of an ohm in my parts box short that across the leads of the cell and measure the voltage across that. I usually use test clips but I have some fairly thick ones. The resistor would ideally have been rated at a Watt or so of power dissipation, as from Ohms law. This would not be accurate for measuring the current, but I would expect the voltage to be at the cells max power voltage or higher across the resistor. This was not really useful for determining the exact current, but was useful for batching cells of similar current together.
Joestue's method is much better, just short the segment of ten gauge wire across the cell and measure the voltage across the wire, again, with the cell in full sunlight - aimed at the sun at high noon. If you have an approximately 1 milliohm resistor, you should see a voltage, from V = I*R, with the I at about 8 Amps, and the R at 1 milliOhm of .008V
I just calculated that pure copper ten gauge solid wire should have a resistance of .00099993 Ohm's in a one foot length. It should make a pretty good measuring tool for this purpose. There is likely some variance in commercial wire, but it should be reasonably close and make a fairly accurate measurement.