Overvolting overamping alternator - Team Camaro Tech
Troubleshooting Diagnosing problems done here.

 
LinkBack Thread Tools Display Modes
post #1 of 6 (permalink) Old Sep 4th, 10, 08:16 AM Thread Starter
Senior Tech
Timothy
 
Join Date: Sep 2007
Location: San Antonio TX
Posts: 1,804
Overvolting overamping alternator

This may be a stupid question but as a mechanic I learn as I experience things. We had a battery and alternator die simultaneously. The car has over 100k. The battery was 2 yrs old.

I replaced both at autozone and the wife was off and running again. About 3 weeks later she calls me and says the car wont start. So I go out to her and try to jump the car but the alternator is not putting out enough juice to keep it running.

The next day I look at the alternator and there are signs of overheating. I take it back and they give me a replacement. But Im afraid that ive just killed 2 alternators and I may fry this one too. This time I measure the output at the battery and it was up to 20+ volts and climbing! Needless to say, Yikes!

I read possible causes could be a bad connection somewhere or short in the main power wire from the alt and Im gearing up to start tracing wires. As Im disconnecting the battery I notice the negative terminal seems a little crusty so I wire brush it. Also with those little pads they sold me it wasnt sitting down all the way on the terminal and may have been loose. After fixing this im now getting 14v at the battery.

So my question, can a loose/dirty negative battery clamp cause an alternator to run at 100% and kill it?

My 69 RS/SS 396 Project -
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


"I may be dumb but I aint stupid"
Microgiant is offline  
Sponsored Links
Advertisement
 
post #2 of 6 (permalink) Old Sep 4th, 10, 09:51 AM Thread Starter
Senior Tech
Timothy
 
Join Date: Sep 2007
Location: San Antonio TX
Posts: 1,804
Re: Overvolting overamping alternator

I found troubleshooting steps for alternators and it stated that for a high reading the likely cause is a loose/dirty neg battery cable. When people tell you this can cause problems they mean EXPENSIVE problems. Another lesson learned the hard way as I rarely (edit: never) cleaned those. I just hope that there are no more problems.
Microgiant is offline  
post #3 of 6 (permalink) Old Sep 4th, 10, 01:27 PM
Senior Tech
Steps
 
Join Date: Dec 2005
Location: New Zealand
Posts: 13,321
Re: Overvolting overamping alternator

Dirty, corroded connection in and elecrical system will cause blubs to blow, even slow over time, starting problems....damn near any connection thats poor will cause problems, so why would one A55-U & ME not with the alternator?

Replacing anything it is a matter of routine to clean/replace connections, threads what ever. If not one can garantee Murhpy will step in at the worst moment a screw you up.
Murphy is your best friend...if you listen to him.

My Spelling is not incorrect...it is creative

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Steptoe is offline  
 
post #4 of 6 (permalink) Old Sep 5th, 10, 04:49 AM
Gold Lifetime Member
Harry
 
dawg's Avatar
 
Join Date: Mar 2004
Location: Colebrook CT.
Posts: 4,054
Re: Overvolting overamping alternator

Im assuming its on a 69 camaro?
if so bad regulator!
get an electronic one!


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

434 stroker
US Navy retired

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
dawg is offline  
post #5 of 6 (permalink) Old Sep 5th, 10, 04:56 AM
Senior Tech
Mark
 
Join Date: Sep 2000
Location: Shrewsbury, MA, USA
Posts: 6,513
Re: Overvolting overamping alternator

What kind of car? Modern cars alternators are controlled by the PCM (powertrain control module) the voltage regulator inside the alternator is suppossed to limit voltage to 15.1V but a problem with the PCM can cause voltages to go higher. If I pull a certain fuse in my car I can get voltages up into the 17s.

Mark Canning
1969 Indy Pace Car
350/300HP RPO Z11

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Mark C is offline  
post #6 of 6 (permalink) Old Sep 5th, 10, 06:54 AM Thread Starter
Senior Tech
Timothy
 
Join Date: Sep 2007
Location: San Antonio TX
Posts: 1,804
Re: Overvolting overamping alternator

This was a 2001 Camry.
Microgiant is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Team Camaro Tech 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.
NOTE we receive a lot of registrations with bad email addresses. IF you do not receive your confirmation email you will not be able to post. contact support and we will try and help.
Be sure you enter a valid email address and check your spam folder as well.



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 post new threads
You may 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