I always measure may voltage at battery with motor running. If it reads 14V or more, then I'm exited. Start you motor, put multimeter on DC 20, touch batt pos to pos and neg to neg and read output. If system is wired correctly and meter reads 14V +/- 1V, you should be OK.
Ideally, Pin 1 should read 12V when motor running, this provides 12V to both sides of bulb and it will not light. If Alt is not charging, Pin 1 will be grounded within alt and will light the light. Reading of 7V should be a dim light and you should also get a low reading at batt. Causes: Low idle, loose belt, bad alternator, alt not grounded thru brackets, system wiring wrong.....bad battery? Do not test Pin 1 with meter ground lead on alt. Touch batt neg.
