I have an odd problem and was wondering if anyone else had seen this or cured it before.
1991 S10 Blazer 4.3L V6
The alternator and battery have been replaced since the vehicle was new. This car has always overcharged the battery enough to make the battery leak, thus it always has trouble with cables corroding etc. With both the batter and alternator having been replaced, I thought that pretty much replaced all of the charging system, but it still does the same thing. This is happening in my parents S10. I also have a '91 S10 Blazer which does not do this so I guess that eliminates the possibility of this being one of those incurable problems. Curious if anyone has any thought on this. Thanks in advance.
The white plug on the top of the alt runs to the volt gauge (or light). The voltage regulator senses the volt (resistance) of the gauge circuit and compares it to the battery voltage (large red wire going to the back of the alt). I had a problem on my moms van where the wires going through the white connector corroded and was telling the alt the wrong resistance for the gauge. Such that the alt thought it was not charging when it was actually putting out full power (also called "full fielding"). So what voltage is it producing? Does it over charge only when first starting in the morning or will it all of a sudden show full power on the gauge? Does the volt gauge agree with an hand held voltmeter that is connected to the battery (13.7 to 14.5v, less then $12, you should have one anyway if you do any work around the house...)? Anyway on a trip back from Florida the alt in the van started to full field. Pulled over and yanked off the white connector (turning off the alt). Drove to a pep boys in Florence SC (about
2 hrs away in the correct direction, aren't diesels great) and changed the white connector with a pig tail that they had for that reason. Never had a problem again and that was 14 yrs ago. So see what voltage it is producing, if more then 14.5 volts then check the leads for the white connector (where it plugs into the alt) and clean them with a wire brush. If this fixes the problem then go to an auto parts store and get a pigtail and change the whole end. Once they start to corrode they continue to do so until you replace it. Maybe somebody else will post with more options.
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