I start the car (84 kjet turbo):
the alt light is off, 10 volts on the voltmeter
I rev the engine:
the alt light comes on, 14 volts on the voltmeter
the tach reading is off by about 300 rpm
when I pull up the emergency brake the tach drops to zero and the alt light gets brighter. It stays this way even at idle after revving.
Sound like a ground problem? I have to dig out my voltmeter, but the alternator must be working if I am getting 14 volts on the dash voltmeter. Oh, yes the belts are intact and tight, Newer (used) alternator with brushes replaced about a year ago, engine wiring harness replaced (although it is homemade).
It just does not make any sense, the light and the gauge are saying the opposite.