Why does the engine die when I plug the alternator in?

1988 BUICK CENTURY
75,000 MILES
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EXGI
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88 Buick Centry 2.5 TBI starts and dies, unplug the alternator and it starts and runs Ok. Plug the alternator 3 wire connector back in and the engine dies. Voltage starts to increase when alternator is plugged in before it dies. IAC seems to to be working because it adjusts engine speed when A/C is turned on. Why does the engine die when the altenator is plugged back in, what am I missing??
Aug 13, 2012 at 2:19 AM
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ASEMASTER6371
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computers hate voltage spikes and thats what you are doing. dont ever do this again as you will burn out modules.

why are you doing this??? what issue do you have

Roy
Aug 13, 2012 at 2:30 AM
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EXGI
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Why does it start and die with the alternator connected?? The alternator has been replaced, battery swapped, ECM swapped and still does same. Runs with alternator disconnected, starts and dies when it's connected. Old pro link connected up, ECM shows 14,4 volts when it dies. Has no fault codes.
Aug 13, 2012 at 3:15 AM
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ASEMASTER6371
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did you use a used or rebuilt alternator??

Roy
Aug 13, 2012 at 10:07 AM
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DJCL
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Check the alternator riple. To much ac voltage out of the alternator will do that
Aug 13, 2012 at 11:55 AM
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EXGI
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It's a rebuilt alternator from Auto Zone. The old alternator did the same thing as the new one, no difference.
Aug 13, 2012 at 12:55 PM
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DJCL
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Is the charge lamp working
Aug 13, 2012 at 11:15 PM
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EXGI
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Yes, the charge indicator light is working.
Aug 14, 2012 at 11:29 AM
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DJCL
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Have that alternator tested on the car for ac ripple. Whar is the ac volt in milly volts reading
Aug 14, 2012 at 12:38 PM
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