[SoCal LS-L]

Since they dim it seems the starter IS getting amperage...... the only conclusive test is to make sure your main cable to the starter is cleanly contacted there, then hook up a multimeter to the much smaller signal wire (the only other wire besides main at starter) and look for 12 volts when you try to start the car. If you get the 12v signal when key is turned and the main battery connection is good at the starter, then you have a bad starter.