2002 Ford Taurus 6 cyl Front Wheel Drive Automatic 130000 miles
2002 Ford Taurus SE 3.0L V6 130000 miles, the alternator drops out intermittently. The alternator is a rebuilt one from a reputable shop, they have inspected it and found no problems. Battery is the second brand new battery, the first died from being discharged too deeply. The problem seems completely intermittent and I can't reproduce it, it just happens randomly. When working it charges beautifully, it regulates at 14.2V and drops to 14.1 with headlights & ac on.
The diagram from Chiltons & Haynes manual both list the alternator as having a Yel/Wht charging wire, an Org/Lt Blu wire which goes to battery, Lt Grn/Red which goes to instrument cluster, and Wht/Blk wire which goes back to alternator on cars w/ 3.0L 12Valve & FFV only.
This alternator actually has Yel/Wht which is charging line to battery, Or/Yel which goes to battery, Lt Grn/Red which I can't figure out, and Gry/Wht or Yel which I can't figure out.
Anyone know what the wires actually go to? It doesn't seem to quite match up with the diagram, neither the color codes or the signals. The Grn/Red line seems to change with varying load, like the comptuer feeds the alternator some regulating voltage, I.E. When headlights are switched on, there is a few volts on the line until it brings the battery up to 14.2V, then it drops off. I assume the Gry/Wht or Yel line goes to the instrument cluster, as when the alternator was in fault, the line was.6VDC which would turn the light on, and when it is working it is 4-6VDC.
I'm out of ideas, I'm just trying to help a guy who's down on his luck and just lost his job. He can't afford a new alternator, and I'm not sure if it's even bad. He doesn't know why it was replaced in the first place, but my suspicion is the original may not have been bad. At this point, I think he may just have to replace the alternator again, but if I can find out what the lines actually do or at least where they go I may stand a chance.
Saturday, February 13th, 2010 AT 7:16 PM