2000 Silverado intermittent alt light

The charging system went down in my 2000 Silverado (small V-8, 4x4, manual tranny). I replaced the battery and alternator and then figured out it was a defective isolator I had installed a few years ago because I occasionally tow a dump trailer which can draw current from the truck to charge its own battery. So after removing the isolator the system charges at 14 plus volts (with a new alternator) and the battery is fully charged BUT randomly the alt light comes on for a few seconds to about a minute at a time. It does it maybe twice per hour with no pattern I can detect, and when it comes on the alt is still putting out over 14 volts. Any ideas ????

John

Reply to
Doctor John
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I am going to take a guess that maybe you have a few bad diodes in the output rectifier on altenator which would limit its current output, not voltage. Have you altenator load tested and see if it is up to full spec.

Reply to
SnoMan

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