Posted by JohnD [71.246.89.162] on Monday, April 29, 2013 at 06:09:16 :
In Reply to: altinator question ( charging ) posted by junkyardog [72.64.8.205] on Sunday, April 28, 2013 at 18:27:31 :
It is true if the alternator has an internal regulator. Find the "D" shaped hole in the back of the alternator. Inserts a small metal screwdriver tip into the hole about 1/2 inch. You will feel it touch a metal tab. While touching the metal tab. Move the screwdriver handle so that the blade is touching the internal tab while also touching the side of the d shaped hole. You are grounding the rotor to give it a command to put out full charge, thus bypassing the regulator.
This test is done with the engine running at fast idle, and watching a voltmeter attached to your battery. If the battery has low voltage (say 10 volts or less) you should see it begin increasing by the tenth of a volt pretty quickly while you do this yest.
All this does is bypass the internal regulator to see if the alternator itself is working. Even if the test proves the alternator is bad, you still need to take it apart to change the regulator.