How do I use a handheld alt/batt tester?

[eremoy]

i have this alternator/battery tester that has a metal point at the top (red) then a cord with a rubber stick at the end (black). It has no internal battery and is said to run off the cars power. How do i use this thing though?

It has two scales: battery (engine off) normal, high, and low. And: Alternator (engine on) normal, high, low.

thanks!!!

 

[Uneek]

Without a picture, my guess would be the red lead goes to the positive terminal of the battery or alternator and the black would be ground and/or the negative side of the alternator or battery.

 

[eremoy]

yeah i tried that, didnt work. then i figured out how to take the cap off the negative end lol! works!