Taurus Car Club of America : Ford Taurus Forum banner

How Good is a Parts Store Alternator Test

18K views 4 replies 4 participants last post by  BigWorm 
#1 ·
I just wanted to post the most recent experience I had with testing a rebuilt alternator at four different parts store. I recently rebuilt a 6g alternator on my 2006 Taurus with 145k miles. Here is the original thread, http://www.taurusclub.com/forum/82-...-vulcan-taurus-alternator-wear-145k-mile.html

I wanted to post the results of the testing because it indicates that you should question the test results and take it to a few places. The test results could cause cause you to waste a $150 on a new alternator.

This is my experience:

I took my rebuilt alternator to AutoZone to have them test it before I installed it in my car. They hooked it up and ran the test and it failed. It failed on the voltage regulator and the test equipment does not give any reason, so at this point I was disappointed.

There is a O'Reilly Auto parts one more block down the road. I took it in there and they tested it. It passed on all items and voltage was 14.81 volts which is what it was before the rebuild.

I decided to take it to Advance Auto Parts which was five miles away for a tie breaker. That was really no help because they ran the test and it failed on every component in the alternator. The rectifiers failed, stator failed, rotor failed and voltage level failed, however voltage regulator was fine. He reran the test and was pressing on the alternator to give more belt tension and guess what it passed on all items. He tried it a third time (not pressing on the alternator) after punching in a new code in to the test machine and it failed on voltage regulator.

So after three places testing I got two passed tests and three failed tests. I plan on taking it tomorrow to the Advance Auto Parts which tested my original first rebuild and have it tested for the forth time.

The interesting thing at O' Reilly's Auto Parts the counter guy spun the alternator by hand and said, " The bearings are bad, I hope it doesn't seize up while I test it". I didn't tell him I just rebuilt it with all new bearings.

I attached the O' Reilly's and Autozone test reports. Advanced said they could not give me a print out of the tests.

I went to a different Advance Auto Parts today and had the alternator tested since the experience previous experience with multiple failed and passed tests. They put it in their machine and ran the testing. It passed all tests and they ran it three times.

So the lesson I learned is don't except a failed test at just one parts place, take it to a few if you don't want to waste a $150 on a new alternator. Total number of places I took the alternator to be tested was four, with two places testing good, one place testing bad and one place testing both good and bad.

I installed the alternator and it works fine in the car.
 

Attachments

See less See more
#2 ·
None of them know what they are doing, that's the problem. Depending on what the selected load is, the alternator may or may not pass. I think the AutoZone test said 110 amps, and I forget what the alternator is rated for. Making sure the test is run properly (correct load, belt tension, etc.) is also important, and many parts stores employees lack the diligence to ensure this.
 
#3 ·
They do input the store part number to get the right adapter and then they select whether it is a shelf unit or customer unit. That may be the difference between specifications like 110 amps of a store unit and 105 amps of OEM. The store that had the worst belt tension adjustment was the one that said everything internal failed. He pressed on the alternator to tension it more and it passed everything. There is also a choice between a V belt and a serpentine belts. The one ran the first test on a V belt until I told them it was a serpentine.
 
#5 ·
the testing equipment is only as smart as the person operating it.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top