[TR] Positive or Negative Earth

[Randall]

> Attach one lead of the light to a known ground and try the other lead on both
> terminals.
> Provided the battery holds charge, the one that makes the light glow is
> positive!

That's true only if the car is negative ground.  If the car is positive ground, then the one that makes the light glow is negative.

The advantage of the meter is that it will tell you polarity.  A test light lights the same either way.

Randall