Alternator problem
07-28-18, 09:02 PM
#1
Rookie
Thread Starter
Alternator problem
Once in awhile if I drive my 2001 es300 in city, turning off and starting from store to store, the alternator quits charging at full. Let it cool for half hour or so, then charges as it should! Using voltmeter. Drops to 11.75 ish when not working right. After cooling, above 13.5 or so.
07-28-18, 09:45 PM
#2
Lexus Champion
How many miles on your car? When the brushes wear down they act like that, alternator will charge sometimes and of course eventually will stop altogether.
07-30-18, 04:50 PM
#3
Rookie
Thread Starter
Sad part is that alternator is about a year old from local auto parts store. Guess I have to time it just right to have them test when charging is low. No way to check that problem otherwise is there?
07-30-18, 04:54 PM
#4
This sounds common for auto parts store alternators. The voltage regulators are often poor quality and fail. Take it in when hot and they have a clamp-on tool for diagnosis. Of course, you will get the same poor quality oart as a replacement. You could get a good VR and install it, of course. Replace it soon to reduce the battery damage and possible electronics damage a bad VR can cause.
07-30-18, 06:35 PM
#5
Intermediate
Napa has *very good* reputable alternators. They are a bit more pricey, but that comes with quality.
Last edited by wmj259; 08-18-18 at 08:53 PM. Reason: spelling "very good" instead of "week"
07-30-18, 09:01 PM
#6
Last time this came up, I bought the VR and some brushes and a bearing from RE Auto electric in Tacoma, WA. it was maybe $75, mostly the VR, and rebuilt it myself. They do mail order.
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