[jim2000ls]

Followed this procedure to replace the alternator in my 2000 Astro on Monday. It was a great help - especially the tip to press the sleeves to give a little more room to drop the new alternator in.

This board has been a great help to me over the years!

 

[Vanjoe]

Great write up here and helpful added comments. I just did an alt replacement. I have been watching and listening to my alt for a year. On a trip it just quit, $150 for extra miles after my towing coverage :banghead:
I decided to go with the truck alt that's 145 amp and am happy. I did use a used one so if it didn't work out , I wouldn't be out so much money. Also did the Big 3. I added a ground to the alt bracket behind the left mounting bolt to the frame with a frame to body ground. Origonal battery ground to engine is at least 4ga and I had added a body ground years ago with my first amp. Next I will replace the wire from battery to the underhood fuse box and will look at new wire to the blower. I do see alot of small ground wires near headlights that just look too small.
Test ride last night..... NO, my headlights do not seem brighter. BUT, a solid 14.4 ? on the gauge, driving, at idle, with nothing on, with everything on!!!! Awesome! One problem..... my rear heater fan is rather obnoxious now at full speed. I guess full speed is a bit faster now.
The BEST HELPFUL INFO on this thread was to use a bolt to withdraw the metal sleeves before installing the new alt!
My helpful hint is USE DIELECTRIC GREASE on EVERY CONNECTION, BOLT. I used it last time I did plugs,wires,cap,rotor,coil and 3 years later my coil, wires are good to go still!!!
I do see a lot of brittle insulation on many different wires due to engine heat. The small alt wire needed a fix.... slit open a flexible hose, filled it with silicone and zip tied it over the wire.

One note on the upgraded alt, it is tight to the cruise/throttle cables bracket and with a new 4ga wire from alt to battery, it needs to be placed in an exact spot(the 4ga wire).

I used to have trouble if I idled a while with both heaters or ac units running. volts dropped a lot. This upgrade fixed that.

Question...... what size fuse to install in the line from the battery to the alternator? I am guessing I need a 150 amp fuse as the alt is 145amp. And I need new battery connector bolts for all these extra cables. I have top and side posts but I would like to clean it up for using just side posts. ANyone have a nice set up for this?

 

[vintagerider]

I had to replace the alternator this past weekend on my 2001 Safari. I guess the original alt wanted a rest after 251,000+ miles. Thanks to the easy to follow "how-to" by Chemist and the spring clip tip from Duck Hunter, the job was fairly simple and straightforward. New belt, tensioner pulley and idler pulley while I was in there. This board is an invaluable resource to keep our vans rolling along!

 

[billsnogo]

Older topic, but still need to give a major thanks. After reading some people complain about it being a PITA, I found it pretty easy, but MUCH easier after reading this post. The tip about using the bolt to push the spring pins out made dropping the alternator in cake walk, otherwise trying to muscle it in would have been a booger. Also so worth the five minutes to remove the upper radiator fan shroud :thumbup: way easier to access the front of the engine. Don't know how hard it is for you guys with the third bolt, but for us guys with the two bolts, it is easy peasy :banana:

thanks for making this job low stress!

 

[LAZ 1]

Just took my 98 Safari into MIDAS for a wheel alignment.

Strange coincidence, but the next day I heard a NEW sound coming out from under the hood.
Sort of a Humming/whirring noise, similar to a supercharger spooling up, that increased with RPM.
HMmmmmm??

Thought it might be power steering pump low on fluid or possibly the alternator.

Sure enough, next morning after a 200 km road trip, with both headlights and A/C on high, my van would not start.
Dead battery.
Did not notice any lights left on so ....?

Charged the battery overnight, and it came up to 13 V.
Checked the charging output at idle with a multi meter and it is at 14.2 V.
Dash gage shows 13.9 V.

So now both the battery and the alternator seem OK??

Looked up the repair receipts and the alternator is a replacement BOSCH, 10 yrs old, with 130 Km on it.

Hopefully it is not time to do a re and re on the alternator.
If I do have to do a replacement, glad to find the detailed instructions in the thread here on the site.

 

[Lumpy]

Hmmm...

How about jerk the cables and connections around. Retighten, clean etc. Maybe the alt is doing it's thing when the van is sitting still but when it's on the road it's having trouble making the connection.

Lump

 

[LAZ 1]

Midas checked both the alternator and the battery.
Battery tested out as good, alternator NOT good. Only putting out 12V.
They say it is probably a blown diode.

I have A SPARE PARTS VAN with low Kms on it so will pull the alternator tomorrow and replace it.
OH BOY!!

 

[Lumpy]

Midas checked both the alternator and the battery.
Battery tested out as good, alternator NOT good. Only putting out 12V.
They say it is probably a blown diode.

I have A SPARE PARTS VAN with low Kms on it so will pull the alternator tomorrow and replace it.
OH BOY!!

Way to go. Check the simple stuff. Should ALWAYS be the first step.

When Midas checked the alterntor, did they remove it from the van or something else?

Lump

 

[AstroWill]

Checked the charging output at idle with a multi meter and it is at 14.2 V.

Interesting how it was working when you tested it, but failed under their test.

 

[LAZ 1]

Interesting that it failed the day after the van went in to Midas for a wheel alignment ...
coincidence??

In any case, I swapped in another alternator from my spare parts van. Voltage now reads 14.5V at idle no load. Under full load, wipers, lights, fan, still reads 14.2V.

Old alternator did read 14.2V at idle, but under load dropped to 12V or less. So it appears I DID have a bad alternator. Plus the odd noise from under the hood is now gone.

THANKS for the advice on pulling the sleeves out a bit. Made it much easier. Two hours to remove two alternators and reinstall one used alternator. Midas quoted me close to $400 parts and labor with a REMAN alternator. Quite a saving for a couple hours work. And the rain held off until just after I finished.
BONUS!!

 

[keith92ext]

does the 92 have the third back bolt? i think i might be missing back of the bracket.

 

[chevymaher]

does the 92 have the third back bolt? i think i might be missing back of the bracket.

My 90 and 94 brackets are the same and have a bolt in back.

 

[keith92ext]

everyone with a 92 make sure you have that third bolt going thru the steel part of the bracket in the back..otherwise your bracket will snap like a twig and luck finding a new one. not sure what other years have this type.learn from my mistake.

 

[95AstroLT]

Thanks for the tutorial! Gave me an edge when replacing the alternator in our 97 Safari today.

Definitely easier with the extra steps of removing the air cleaner and upper fan shroud first. I also replaced the pulley on the tensioner since it seemed just a little wobbly, but the new one felt the same so maybe it was OK after all. Oh well, cheap insurance.

Only difficult part was the passenger's side bolt was corroded and fought me the entire way out - took about 45 minutes just to remove it! Probably could have zipped it out with an impact, but I was a-scared of messing up the threads so took my time.

I did find that a 6 point 1/2" socket worked well. Began with the 13 mm as suggested but since I had to pull so hard on the passenger's side bolt the 13mm 12 point seemed to indicate it wanted to slip.

Now producing 14.5 volts at idle, no load; 14 v at idle with lights and fans on. Was 13.5 and <12

Thanks again!

 

[mweir]

I want to thank chemist for this excellent article. I had assumed I would have to do a lot more disassembly, but the replacement went smoothly following his method. I would add one additional bit of information. I see another reader mentioned sleeves in the alternator mounting ears. In my case (a 2005 with CS alternator) the casting that carries the alternator has them in the front mounting holes. They are split steel sleeves that can slide in the casting to accommodate manufacturing dimensional differences in the alternator mounting ears. When the mounting bolts are tightened down, they are actually sliding the tolerance sleeves against the alternator mounting ears. They are tight when you remove the alternator, which accounts for the usual need to pry it out. You shouldn't have to force it back in, however. The photo below shows how to press the sleeve forward, giving clearance for the alternator. I used a 3/8 inch grade 5 bolt and hardened washer, with (I think) a 14 mm socket to clear the spacer. You only need to tighten the bolt/nut a turn to achieve generous clearance, so the alternator drops back in easily. Hope this is helpful.

 

[AstroWill]

Good tip, thanks for adding it to the thread.

 

[Old Barney]

Just replaced mine on the 2001 with front and rear AC lines. Kind of wished they would have sied the room better getting the socket/extension past the heater water switch was not possible without bending the hose at 90 degrees took about three hours of cusses, other words for the engineer, prying, once I got it out I took the two spacers out cleaned and lubricated them for easier installation I used a long bolt and socket to draw the spacer up tight. the alternater dropped in easily. BUT getting the driver side bolt out was a trip as at some time water attack the bolt and rust covered it I used PB and in and out a few times then reverted to my 3/8" air ratchet which made the situation much faster. My new unit came from china and the stud is much smaller than the original and metric not sae. The original nut took a 1/2" wrench to remove and another under the wire as the stud was turning.
Now I have full output and regulates as it is supposed to I have a slight ripple of about .06 millivolts. on the scope across the battery when taken off idle sped up slightly the AC component is now gone. Radio sounds good on AM too. My gas gauge, and temp still dead and the shift indicator still doesn't work after 30 seconds of just key on without engine running. Instrument panel may have been damaged too.

 

[Kwillsound]

This thread was very helpful today! I'd only changed an alternator once before on my old Chrysler 5th Ave. that had tons of working room, but this one looked a little more complicated to get to. I was able to read this thread as I had my coffee this morning, assemble the tools, and knock it on out. It was also a great opportunity to change out the old serpentine belt. All systems go. Thanks everyone for your experience with this, and double thanks for the step by step instructions and pics!

Cheers!

 

[AngryPunk]

Great guide! Saved my *** today.

A coupe of minor things.
* I didn't realise it was the square hole that one uses to take the tension off the serpentine belt. So I accidentally loosened the nut that holds the tensioner on. I now see what you meant by 3/8 entension bar.
* The cables are WAY easier to get off once the bolts have been removed. Don't even try while it's bolted in place. Just be careful getting it out.
* Getting the new one in was a pain in the butt. I don't own a mallet and couldn't get leverage so I used a piece of wood and hit it with the hammer. That did the trick nicely.

Hope that's helpful for people. Took me a few hours but I had to learn each step as I went.

 

[Cptdondo]

I’m crashing and burning on step 4 - remove the bolts. They are rusted solid. From feeling around it feels like the bolts protrude about 1/4” past the housing. That’s a lot of rusty thread to break loose.

I’m planning to get 6 point sockets and drench the bolts in PBlaster. Maybe take a punch and tap on the bolts to try and break them loose. Any other suggestions?