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2002 Silverado alternator problem

Frozen001

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Frozen001 Enthusiast

Frozen001

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Posted

My father has a 2002 Silverado 1500 5.3l ext. cab. He had to replace his alternator some time ago and he now has a problem with his lights going dim for every couple of seconds. His voltage guage drops a bit when this happens. Anybody else experience this problem?? It is almost as if the alternator drops out every couple of seconds. He has had both his battery and alternator tested, both checked out fine.

pm26 Senior Enthusiast

pm26

Posted
Posted

Who checked out the alternator?

 

If everything (battery and alternator are properly tested and work fine, I would carefully check all battery cable terminals on both ends, especially negative cable terminal to the engine block/truck frame. Corrosion or loose connection at that point can cause all kinds of strange electrical problems.

 

The problem appears to be intermittently malfunctioning voltage regulator inside the alternator. Is the new alternator a cheap Auto Zone or Advance Auto parts special?

Bish Senior Enthusiast

Bish

Posted
Posted
My father has a 2002 Silverado 1500 5.3l ext. cab.  He had to replace his alternator some time ago and he now has a problem with his lights going dim for every couple of seconds.  His voltage guage drops a bit when this happens.  Anybody else experience this problem??  It is almost as if the alternator drops out every couple of seconds.  He has had both his battery and alternator tested, both checked out fine.

 

 

 

 

Two of my alternators failed in exactly the same way. Original (130amp) went at about 50K. Napa replacement lasted 60K before failing in exactly the same way. The third one (a 210amp Alterstart) has been going strong for 40K+. I think it is the internal regulator/rectifier that is failing.

 

Symptom for me was intermittent. Could be driving on highway for hours and sometimes the lights would dim for a fraction of a second and the voltmeter would bounce down then up. It would happen more when starting up cold but would eventually go to normal. I replaced it because I drive long distances in the middle of nowhere and did not want to take a change of getting stranded. I actually drove around with a spare in my truck for about 10K miles waiting for the original to completely fail. I ended up replacing it before complete failure.

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