ford windstar tail light problems

My drivers side tail light won't work.  I replaced the bulb, nothing; I took the bulb from the passenger side that is working, still nothing.  I measured -12V at the plug (same as passenger side).  This I find weird, because the 3-pin plug is labelled GND, Major, Minor.  I thought the GND was ground, minor is for the tail light, and major is for the brake light.  I have a good Fluke DMM (179).  I don't understand why there is -12V with the black lead on GND and the red lead on minor and major.  The brake lights both work, and there is -12V on both major and minor even when only the tail lights are on without the brake lights on.

I then cut the wire from the GND and turned on tail lights, touched the GND wire from the light socket directly to the frame ground, and still no light on.  I then touched the cut cut wires back together and the light worked.  So I thought I somehow fixed this, so I crimped and soldered the wire back together, but the light still won't work.

If anyone has any ideas, please let me know.

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inallalone

I forgot to add that it is a 1999 Ford Windstar, 3.8L

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inallalone

have someone press the brakes and check the wires

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boxead78