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Re: Alternator Testing

To: Alan.McEachran@anixter.com, spitfires@autox.team.net
Subject: Re: Alternator Testing
From: Dave Chu <dave@ece.concordia.ca>
Date: Tue, 06 Jul 2004 00:30:33 -0400
In message <OF3C93391E.9EF166BC-ON85256EC8.004CD1E2-85256EC8.004E0210@anixter.c
om>you write:
>I suspect the alternator as my problem.  My Haynes says I can do a rough
>check on it by connecting an Ampmeter in series between the brown wire from
>the alternator and the starter.  I'm no electrical whiz, but I do have a
>nice Fluke Digital Multimeter that I'm sure I could fry if I fought the
>need for advice.

You should first check if your battery is still good.  Try to charge the
battery and see if it will hold a charge.  You will have to put it under
some load such as turning the head lights on and use a multimeter to
get an voltage reading.  It should be above 13V after it is fulling 
charged and it will go down a little but stay about 12V when you turn the 
lights on without the engine running.

The next item to check will be the alternator.  With the engine running
the voltage at the battery should be above 13.5V.  Never disconnect the 
battery while the car is running, that could damage the electronics 
inside the alternator.  Another quick way to test your alternator is to 
remove it from the car and go to your local Canadain Tire and have them
test it at the auto parts counter (you can also bring your battery at
the sametime to have it tested).

If the problem is the alternator you can rebuilt it yourself.  The most
likely culprit are the brushes, which is pretty easy to replace and I
don't think you have to do any soldering unlike the starter.  But you should 
make sure the bearings are in good condition at the sametime.  The
parts can be bought online from Obsolete Automotive in Point Edward, which
is beside Sarnia; http://www.obsoleteauto.com/ . 

Hope this is of some help, best of luck.

Dave                                                  |\ |     | |      
_______________________________________/\  /\  /\_____| \|_____| |____________
Dave Chu                                 \/  \/       | /|     | |  
Dept. of Elec. & Comp. Eng.                           |/ |     | |      
Concordia University              (514)848-2424 Ext.3115    Fax:(514)848-2802 
1455 de Maisonneuve W. H961       Email:dave@ece.concordia.ca
Montreal, Quebec, Canada H3G 1M8  http://www.ece.concordia.ca/~dave/addr.html
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