? GM alt. not holding up? - Off-Road Forums & Discussion Groups
Suzuki GEO All Discussion of all things, Suzuki and GEO

 
LinkBack Thread Tools Display Modes
post #1 of (permalink) Old 08-09-2002, 09:28 AM Thread Starter
 
Join Date: Nov 2001
Posts: 734
Thanks: 0
Thanked 0 Times in 0 Posts
 
? GM alt. not holding up?

Hey,
This is my third GM alt. in two years on my zuk. Is this normal?

All have quit working, the bearings were good in them, the belt was not to tight just a normal chevy 78 amp alt.
On the rebuild paper work it shows the alt. putting out73 amps at 4,000rpm.........hum.....the chevy engine the alt was made for runs about 2,500 rpms at 60mph .
My zuk runs about 4,000rpms at 60mph


Do you think I'm wearing out the alt because it wasn't meant to run at 4,000rpms all it's life?
The zuk is my daily driver so it's always at 4,000rpms in fifth gears

DOABLE is offline  
Sponsored Links
Advertisement
 
post #2 of (permalink) Old 08-09-2002, 10:15 AM
Can't Get Enough
 
freebird01's Avatar
 
Join Date: Oct 2001
Location: Myerstown, PA
Posts: 1,334
Thanks: 0
Thanked 0 Times in 0 Posts
 
Re: ? GM alt. not holding up?

double check to make sure your wiring is correct...did you do anything goofy with it? like jumpstart another car? i did that and fried the diode in mine....twice...these chevy alternaters are very senstive to voltage spikes....a bit too much voltage and BAM (like the emril impression? lol) there goes the diode or the regulator...
freebird01 is offline  
post #3 of (permalink) Old 08-09-2002, 10:22 AM
 
Join Date: Dec 2001
Posts: 1,604
Thanks: 0
Thanked 0 Times in 0 Posts
 
Re: ? GM alt. not holding up?

the first one i had i burt up in 3 months it would never stop charging
but the second one was fine when i did the engine swap it had 3 months on it but it cycles
i have not put it on the 1.6 yet and might not still dont know
GA_ZUKI is offline  
Sponsored Links
Advertisement
 
post #4 of (permalink) Old 08-09-2002, 10:23 AM
 
Join Date: May 2002
Posts: 2,890
Thanks: 0
Thanked 0 Times in 0 Posts
 
Re: ? GM alt. not holding up?

Are the diodes, or brushes dying? What is its output voltage? How about under load? Is the regulator doing its job right?

You need to look at the stock chev pullys and what you have now. The pullies are not near a 1:1 ratio, and the zuk has a different crank pully dia. to boot. Actually the alt should be spinning way faster than the motor, but that doesn't mean its right. You might be in the ballpark, or it could be over or under reving the alt for long life. That alt should last for 100K miles without too much problem. Time to do a little math.

Also what is its operating enviroment? hot and dusty? burried in water a lot? Are you in a heavy rainy area like parts of Oregon/Washington?
outlawmws is offline  
post #5 of (permalink) Old 08-09-2002, 11:53 AM Thread Starter
 
Join Date: Nov 2001
Posts: 734
Thanks: 0
Thanked 0 Times in 0 Posts
 
Re: ? GM alt. not holding up?

Thanks for the replies the pully diameter is the same as on the samurai alt.
Both times it has been the dio trio that failed, The first time after using my warn winch to pull out my brothers FJ40(that thing is sooo heavy) the alt failed.
The next time out of the blue I turned on all my off road lights ( like I've done many times before) pooof no more out put.
Haven't sunk the zuk in a while , It's hot where I live but It's hot everywhere,and yea we get a shower just about every afternoon .
Don't know if this has any effect on the preformance of the alt?
DOABLE is offline  
post #6 of (permalink) Old 08-09-2002, 07:53 PM
Moderator
 
dparker's Avatar
 
Join Date: Jan 2001
Location: Arkansas.Paragould
Posts: 4,427
Thanks: 0
Thanked 0 Times in 0 Posts
 
Re: ? GM alt. not holding up?

Heat kills the didoes in chevy alts. If the place your getting the rebuilds at are using cheap rectifier packs it will happen over and over .
dparker is offline  
post #7 of (permalink) Old 08-09-2002, 08:26 PM
 
Join Date: Feb 2002
Posts: 670
Thanks: 0
Thanked 0 Times in 0 Posts
 
Re: ? GM alt. not holding up?

I fried 3 in one year! I don't abuse the Sammy's charging system like I do in the Chevy(large sound system). The current unit has been working for 9 months, The only change I made was moving the 10 ga. wire that plugs into the back, from the stock plug to the charging post. Before it was slightly over charging. Now it runs about 14.7V.

I figured the ratio of the 1.3 vs. small block rpm's to be close to the same.....the pulley on the Chevy is like 2" larger, making the alt. spin faster @ lower rpm.

I now use Rotational Dynamics' underdrive pulley, so it spins even slower.

The biggest problem I've had is the bracket I got from RRO. No matter what I do, the alt. works its way loose. On my last trip to Sacramento, the bracket broke in half! The bracket looks beefy, but the alignment tabs create fracture points.
crazycooter is offline  
post #8 of (permalink) Old 08-09-2002, 09:14 PM
 
Join Date: Jun 2001
Posts: 1,628
Thanks: 0
Thanked 0 Times in 0 Posts
 
Re: ? GM alt. not holding up?

It's possible you've got too much voltage drop on the output wire causing the regulator to have to output more current. For 70 amps, you need at least 6ga wire, and 4ga would be better. The factory zuk wire is probably only 10ga, which is only good for 30-35 amps - about what the stock alternator supplies.
If you're still using the stock wiring, I would run a 4ga wire from the post on the back of the alternator straight to the positive battery terminal.

I don't think RPM issue is your problem. If it were turning too fast, you probably would be loosing bearings and not electrical components.
dschwab9 is offline  
post #9 of (permalink) Old 08-09-2002, 09:37 PM Thread Starter
 
Join Date: Nov 2001
Posts: 734
Thanks: 0
Thanked 0 Times in 0 Posts
 
Re: ? GM alt. not holding up?

Good point I'm using 8ga from the alt. to the battery(+) Fine strain cable

"I don't think RPM issue is your problem. If it were turning too fast, you probably would be loosing bearings and not electrical components"

I didn't even think about looking at it that way...damm this board is good [img]images/icons/smile.gif[/img]
DOABLE is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Off-Road Forums & Discussion Groups forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome