ting pulse can damage a multimeter. The voltage on 50W through 400W lamps is at least 2500V, and for the 1000W lamps at least 3000V. Therefore, determine if an ignitor is part of the circuit, and disconnect it before taking an OCV reading. A short-circuit current measurement gives you the highest current the lamp could see. It can also indicate if the ballast/capacitor combination is correct (or if the ballast/capacitor is defective).
To do the SCCM test, deenergize the fixture. Then, use a jumper lead with alligator clips at each end to create a dead short on the secondary side of the ballast; directly at the socket (the ballast acts as a choke and limits the current). One end of the of the jumper clips to the center contact; the other end clips to the screw shell. For maximum safety, use an HLR fuse holder with a 10A GLR fuse in the test wire, because the ballast could have an internal short. Although the fuse could blow, it usually doesn't. But for the few times it might, this precaution could save you from serious injury. While making sure your ammeter is not close to the ballast's magnetic field, since it could distort readings, clip the ammeter around the jumper wire. Next, energize the circuit, and take the reading. If the reading doesn't fall within the specified range, check the ballast input voltage and ballast wiring. If both are correct, the problem is probably a defective/marginal ballast or capacitor or the incorrect ballast/lamp combination.