Grand prix won't charge when it is very cold, why?
Got a new battery. In the summer runs fine.
When it gets below freezing, dash and
lights run dim, and battery lite comes on.
After it runs for a while everything will get
bright and it will charge normally. I ran it to
Chicago from WI twice this weekend, no
problems. I can even shut it off for an hour
or two with no problems. Overnight or for
more than 4 hours in the freezing cold and
it starts fine, but doesn't charge. It will
usually drain the battery before the
charging kicks in. But if I jump it and let it
run until warm, then all is well. Also, revving
it when the battery light comes on will solve
the issue for a minute other two. Once it
kicks in, dash and lights brighten up and
charges normal. Had the alternator
checked[while warm] and it was putting out
possibly a diode in the voltage regulator. with the engine running you should have 13.5 to 14.5 volts at the battery. a multimeter will tell you .
Is that internal within the alternator?
Yes. Put a multmeter on it.
Replaced alternator, problem solved
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