Does anyone know what the voltage readings should be on all three of the terminals on the back of alternator while truck is idleing. I am getting +14.1 at large terminal +13.9 at first small terminal up and -10.7 at the top small terminal I am Checking this with a Power Probe as I dont have a volt meter handy


this is on my 98 Sorry

 

large terminal is alt output and if you have 14V its charging, other 2 wires(smaller) are from the PCM or voltage regulator, their reading would only matter IF your not charging.

do you have an intermidant charging issue??