87 Alternator
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Instructor
Joined: Mar 2007
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From: Red Oak Texas
87 Alternator
I just found out my alternator is dead after eating 2 of my batteries. My question is, has anybody put new brushes in one before and would that fix the problem? Is it worth it or should I just go ahead and pay the $100 for a new one?
Team Owner
Joined: Dec 1999
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From: Lacey WA RVN 68-69
NCM Sinkhole Donor
Get a good-quality remanufactured alternator. Go with AC Delco or even a Bosch unit. That way you have some sort of warranty with it.
There is no real way of telling if it's just the brushes that have gone bad. Alternators have a built-in regulator and that could be the problem.
There is no real way of telling if it's just the brushes that have gone bad. Alternators have a built-in regulator and that could be the problem.
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
You can take the alternator apart and if its the brushes, you can easily see that that is the problem. Also, some parts stores will test the voltage regulator. Diodes can be tested with an ohmeter. Lowest cost way is to take it to an auto electrical shop and have them rebuild it. Most places do a good job. Ask around. I buy rebuilt AC Delco's and they last a long time.
Le Mans Master
Joined: Dec 2000
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From: San Diego, Ca
Pro
Joined: Oct 2003
Posts: 506
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From: Savannah GA
OK, I didn't read the info on rebuilding alternators. The old style SI's are easy to fix. The CS-130 in the 87 is designed as a "throw away". If you have the time you can fix it. It needs more than brushes, it's more than likely the diode bridge and it's soldered in.
My advice; if you replace it ONLY GET ONE WITH A LIFETIME WARRANTY!
Pep Boys replaced mine 3 times! (in 13 years) The last 2 were brand new aftermarket alternators. (They only lifetime new ones now)
Here is what I have found out over the years heat and a weak/low battery is what kills these alternators. If you don't drive it much get a battery tender and you won't have problems. I also replaced the boost fan switch (my 87 has the 2nd fan out front not ECM controled) with a 200 degree switch that helps keep the under hood temps down.
Long ago an auto electric shop told me that generation GM alternator was good for about 85k miles, or 4yrs in front drive and cars without an engine driven fan.
JS
My advice; if you replace it ONLY GET ONE WITH A LIFETIME WARRANTY!
Pep Boys replaced mine 3 times! (in 13 years) The last 2 were brand new aftermarket alternators. (They only lifetime new ones now)
Here is what I have found out over the years heat and a weak/low battery is what kills these alternators. If you don't drive it much get a battery tender and you won't have problems. I also replaced the boost fan switch (my 87 has the 2nd fan out front not ECM controled) with a 200 degree switch that helps keep the under hood temps down.
Long ago an auto electric shop told me that generation GM alternator was good for about 85k miles, or 4yrs in front drive and cars without an engine driven fan.
JS
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