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Alternator Removal/Replacement How-To (2003 Astro)

71202 Views 80 Replies 61 Participants Last post by  Rod's Trucks
5
Replacement of an alternator is a general repair. In my case, this happened around 110K miles. There are ways to know you have a bad alternator before your van dies on the middle of the road. In my case, the battery light came on. A battery test revealed the battery was fine. That left another possible suspect--the alternator...uhg. Looking at the voltage output guage was a pretty good indicator too. The folks who tested the battery told me it should be indicating closer to 16/17, but in my case it was reading 14/15.

Now you may have a short somewhere. But some shops, like Advance, will test your alternator for free, so you're just out some time and sanity in pulling it out. Also maybe your battery just dies when parked overnight. That could be a voltage regulator. Unless I'm mistaken, GM put the voltage regulator in your alternator (different from Ford). A bad alternator may leave you needing a tow. Worse, a bad voltage regulator may also fry your battery, so don't waste time waiting for the nerve to get this done. There's no good reason for a backyard mechanic to fail on this, despite how daunting the job of accessing the alternator appears. No specialty tools are required. It just takes a little longer than on your sedan. To give an idea of what is meant here, this is a pic of the alternator:

It's between the air filter housing, the AC lines and just below the oil dipstick...no reason to be discouraged.

To begin, proceed as follows:

Edit (addition): This should have been number 1--safety first. Disconnect the battery. SWMBO made me do this, despite the fact that I like to listen to the radio as I work... The bolts on the side terminals of mine were 8 mm.

1. Remove the air intake as per this procedure:
http://www.astrosafari.com/viewtopic.php?f=9&t=1142

2. Remove the upper fan housing as per this procedure:
http://www.astrosafari.com/viewtopic.php?f=9&t=1143

3. To remove the belt from the alternator, slip a 3/8" extention into the belt tensioner, and pull up on the rachet. A good pic of the tensioner wasn't possible, but here's one showing the location with extension already inserted:


For more details on how to deal with that belt, refer to the removal procedure, here:
http://www.astrosafari.com/viewtopic.php?f=9&t=1144

4. Using a 13mm socket with extension(s) remove the two alternator bolts, located at the bottom of the alternator:


5. The alternator won't just lift right out. It needs coaxing with a pry bar and sturdy screwdriver, seen behind the coolant hose in this pic:


6. Don't just try to yank it out once you've unseated the part, because it's still attached via two wires.
6a. One is on the top, going in through a harness. Pull the clip out and pull the wire harness.
6b. The other is in the back of the alternator, covered by a slip on rubber boot. Slip the boot off and unbolt it (8 or 9 mm socket if memory serves me, but I may be wrong).

7. Now half the job is done. Pull out the alternator, maneuvering as needed, and taking care not to break the plastic fan. And this is what your left with:


Replacement is the exact reverse of this procedure. To seat the alternator properly, I recommend removing the transmission and oil dipsticks and coaxing with a long socket extension (or screwdriver) and mallet.
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I'll have to keep this thread in mind as my alternator is whining... I'll likely run it til it dies, but yeah, getting close methinks.
Thanks for the great post and pictures, my son and I replaced the alternator,serpentine belt and belt tension pulley on his 97 Astro last week, all went well, we appreciate your help, I went over your steps several times before starting the job, would have taken a lot longer without it.

Thanks again.

Don
I see some slightly incorrect terminology here as well as in manufacturer's ads
when it comes to alternator output.

Alt's don't really "output 100 amps at idle". By themselves, they don't "output" amperage at any speed.
Amperage is a function of the load. The world's largest alternator, at any speed,
into a load that is "asking for" (drawing) ONE amp will output one amp, no more.

Better termininology would be "Is capable of supplying 100A at idle", rather than
"outputs 100A at idle".

A bigger alternator (amperage rating) may be beefier built than the smaller alt.
But unless you have added some kind of extra load to the electrical system, a bigger
alt will output the same current (amps) as the smaller one.

Alternators output 12 VOLTS (or 13.8 or 14.5 or whatever) constantly. They supply
AMPS to whatever extent the load requires.

E=IR

Lump
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Great Explanation Lumpy

Thanks, Jim
I have noticed on some forms you fill out, it asks you to print your name. Sorry I forgot my printing press. (I usually just letter my name in, instead)

How did we, speaking collectively, stray from using correct English. I sat in on an English class and the teacher used the word "can" instead of "may" in an instruction to the class for an answer. Everyone in the class could speak, the teacher was giving permission to the class to speak.

I'm sure there are many more examples of incorrect wording, but it shouldn't come from the English teacher.

Go figure...

Keith
94 Van Guy said:
I have noticed on some forms you fill out, it asks you to print your name. Sorry I forgot my printing press. (I usually just letter my name in, instead)

How did we, speaking collectively, stray from using correct English. I sat in on an English class and the teacher used the word "can" instead of "may" in an instruction to the class for an answer. Everyone in the class could speak, the teacher was giving permission to the class to speak.

I'm sure there are many more examples of incorrect wording, but it shouldn't come from the English teacher.

Go figure...

Keith
This "can" and "may" thing is a really insufferable bit of pedantry, commonly cited by people who don't understand actual issues of language mechanics. Also, I'm not fond of the doctrine of preventing language evolution - why don't you read some Chaucer and see just how much English has changed over the past few centuries?

Fyi, isn't the following sentence: How did we, speaking collectively, stray from using correct English. supposed to be a question? Whuh oh! and you follow it up with a triple preposition in the next sentence: "in an instruction to the class for an answer" Not my idea of elegance. Then, right after that: I'm sure there are many more examples of incorrect wording, but it shouldn't come from the English teacher. What's the antecedent of "it"? It's not supposed to be "incorrect wording", FYI. "They," referring to examples, would be correct.

To go back to an old cliche, those who live in glass internets shouldn't throw stones. C
Astroclyde said:
94 Van Guy said:
I have noticed on some forms you fill out, it asks you to print your name. Sorry I forgot my printing press. (I usually just letter my name in, instead)

How did we, speaking collectively, stray from using correct English. I sat in on an English class and the teacher used the word "can" instead of "may" in an instruction to the class for an answer. Everyone in the class could speak, the teacher was giving permission to the class to speak.

I'm sure there are many more examples of incorrect wording, but it shouldn't come from the English teacher.

Go figure...

Keith
This "can" and "may" thing is a really insufferable bit of pedantry, commonly cited by people who don't understand actual issues of language mechanics. Also, I'm not fond of the doctrine of preventing language evolution - why don't you read some Chaucer and see just how much English has changed over the past few centuries?

Fyi, isn't the following sentence: How did we, speaking collectively, stray from using correct English. supposed to be a question? Whuh oh! and you follow it up with a triple preposition in the next sentence: "in an instruction to the class for an answer" Not my idea of elegance. Then, right after that: I'm sure there are many more examples of incorrect wording, but it shouldn't come from the English teacher. What's the antecedent of "it"? It's not supposed to be "incorrect wording", FYI. "They," referring to examples, would be correct.

To go back to an old cliche, those who live in glass internets shouldn't throw stones. C
touche

Keith
Lumpy said:
I see some slightly incorrect terminology here as well as in manufacturer's ads
when it comes to alternator output.

Alt's don't really "output 100 amps at idle". By themselves, they don't "output" amperage at any speed.
Amperage is a function of the load. The world's largest alternator, at any speed,
into a load that is "asking for" (drawing) ONE amp will output one amp, no more.

Better termininology would be "Is capable of supplying 100A at idle", rather than
"outputs 100A at idle".

A bigger alternator (amperage rating) may be beefier built than the smaller alt.
But unless you have added some kind of extra load to the electrical system, a bigger
alt will output the same current (amps) as the smaller one.

Alternators output 12 VOLTS (or 13.8 or 14.5 or whatever) constantly. They supply
AMPS to whatever extent the load requires.

E=IR

Lump
Kirchoff's current law FTW. well said.
I can be... I may be... Ah heck I am...

Confused.

LOLz, Jim

PS I am glad we have Guys with Brains here. Rock On!!!
Lumpy said:
Alt's don't really "output 100 amps at idle". By themselves, they don't "output" amperage at any speed.
Amperage is a function of the load. The world's largest alternator, at any speed,
into a load that is "asking for" (drawing) ONE amp will output one amp, no more.

Better termininology would be "Is capable of supplying 100A at idle", rather than
"outputs 100A at idle".
:goodpost:
Lumpy said:
Alt's don't really "output 100 amps at idle". By themselves, they don't "output" amperage at any speed.
Amperage is a function of the load. The world's largest alternator, at any speed,
into a load that is "asking for" (drawing) ONE amp will output one amp, no more.

Better termininology would be "Is capable of supplying 100A at idle", rather than
"outputs 100A at idle".
:goodpost:
Replaced the alternator on my 2k today. Removed it last night. The astro/safari site is invaluable. At first I struggled trying to removed the unit from the bracket and thought I better check with this site to see if there was another bracket in the rear I couldn't see. 10 minutes later I had the alt in my hands. Too late for the parts store last night, had a new one in before noon today....about 30 minutes to install.

Lots of good info here.....Thanks, especially for the pictures.

Bill
Yeah, they like pichures here.
yeah pics are cool. They will help a lot when i do my alt tomorrow!!!! They squeal became a groan, and to quote someone else post "sounded like it was screaming :screaming: ck you".

But hey 174,000 out of the origanal, well, kinda saw that coming......
can't wait till I order the lift kit. then everything on it will be new. and then hopefully then...

i

can

stop working on the effing van!!!!

and just drive it places.
This job is way easier with the fan shroud removed. The shroud is very easy to take off. In fact....any repair is way easier if you take the shroud off.
Hey, tomorrow I've got to drop the fuel tank. Think I should remove the shroud first to make the job any easier ?

Bbo
Good one Bert, I like it! :rockon:

:rofl: :rofl: :rofl:
So replacing an alternator on a 95 astro with a AD244 alternator is a good idea?
New to this forum, thought it was a very similar but different one at first, so I end up using both.

Had some charging issues and wanted to thank ' chemist' and the other guys on the first page for posting photos and wrench sizes, etc.

All charging issues sorted out now.
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