Join Date: Aug 2000
Location: Ft Worth, Tx USA
On what are you connecting the test light to on the alt? If you connect it to the large single post on the rear it will light,because this is direct battery voltage.
To answer your question about the doides,if one is out yes the alt can charge but maybe not to it's full potential.The diode is like a check valve in a water line, juice can go through one way but not back.If the doide or diodes are out then juice can come back through causing back feed making the voltage reg stay engagued and run the batt down.
There are 3 postive and 3 negative doides.The alternator makes A.C. current and the diodes convert A.C. to D.C.
[This message has been edited by lnjstreetrods (edited 10-15-2000).]