PT Cruiser Forum  
Advertisements
       

Go Back   PT Cruiser Forum > General Forums > Tech & Performance Forum

PT Cruiser Forum

Advertisements
Old test for bad alternator no longer a guarantee!

 
Like Tree5Likes
  • 1 Post By pt06
  • 1 Post By Busted_PT
  • 1 Post By Carl48
  • 1 Post By rob342
  • 1 Post By rob342

Reply
 
LinkBack Thread Tools Display Modes
  #1 (permalink)  
Old 24 Jul 2013, 08:30 pm
Busted_PT's Avatar
Obsessed Cruiser
 
Join Date: Jan 2012
Location: Beckley, W.V.
Posts: 13,882
Default Old test for bad alternator no longer a guarantee!

So I was having the conversation with a very good friend about the subject of diagnosing bad battery's and alternators. Will Me being a mechanic by necessity, chimed in with the pulling the battery terminal of the battery. If it runs the alternator is good as long it's not intermittent. Friend says are you sure. I was completely sure until he said that. So I go outside put it to the test. It died.So that brings another sure bet into question the battery light. In the past when it's on, go get you an alternator. Now could be the battery. So Did I tell I hat change?
__________________

03 Dream stock___________________________ 04 Touring turbo lite stock_________ 02 Touring stock_____________________ The "Three Amigos"
__________________________________________________ __________________________________________________ ___________Performance, Body and Service, OEM

This Is my project page.
http://www.ptcruiserlinks.com/forum/...oject-1-a.html

This is a great read from one of our own! Badglas
badglas.blogspot.com
Reply With Quote
  #2 (permalink)  
Old 24 Jul 2013, 09:10 pm
Veteran Cruiser
 
Join Date: Mar 2012
Location: darien il
Posts: 4,592
Default Re: Old test for bad alternator no longer a guarantee!

Mine idled for about 3 minutes without a battery (learned as a last ditch effort helping a friend stuck on an expressway at 2am)
Reply With Quote
  #3 (permalink)  
Old 24 Jul 2013, 09:40 pm
Busted_PT's Avatar
Obsessed Cruiser
 
Join Date: Jan 2012
Location: Beckley, W.V.
Posts: 13,882
Default Re: Old test for bad alternator no longer a guarantee!

Quote:
Originally Posted by rob342 View Post
Mine idled for about 3 minutes without a battery (learned as a last ditch effort helping a friend stuck on an expressway at 2am)
Tried it today and my 03 died straight away. Wonder why yours didn't?
__________________

03 Dream stock___________________________ 04 Touring turbo lite stock_________ 02 Touring stock_____________________ The "Three Amigos"
__________________________________________________ __________________________________________________ ___________Performance, Body and Service, OEM

This Is my project page.
http://www.ptcruiserlinks.com/forum/...oject-1-a.html

This is a great read from one of our own! Badglas
badglas.blogspot.com
Reply With Quote
  #4 (permalink)  
Old 24 Jul 2013, 10:59 pm
Mud's Avatar
Mud Mud is offline
Fresh Cruiser
 
Join Date: Jul 2013
Location: south US
Posts: 26
Default Re: Old test for bad alternator no longer a guarantee!

Yea :/ someone told me that awhile back... was disappointed.
__________________
2005 PT Cruiser TE n/a (cool vanilla)
Bought new in '05
-@ <18k (8/1/08) NEW stock radio.
-@ <19k (8/29/08) NEW oil sending unit (dealt w/ since 12/22/06 <9k).
-@ 43k (7/19/13) NEW timing belt & tensioner, water pump, engine gasket pkg, oil pan, head resurfacing.
-@ 44k (9/25/13) NEW oil sending unit.

AMC contributions to Chrysler include not only Francois Castaing, but also the Director of Small Car Operations, who was responsible for the PT Cruiser.
Reply With Quote
  #5 (permalink)  
Old 25 Jul 2013, 03:54 am
Senior Cruiser
 
Join Date: Jan 2013
Posts: 1,253
Default Re: Old test for bad alternator no longer a guarantee!

Busted; in the old days the alternator only needed a regulator [usually mounted on the firewall on mopars] to make electricity. The regulator only needed power from the ignition switch to work. Since there was no other electronics involved [like pcm's] , your test was valid to find out if the alternator put out at least some electricity.

Just a theory: by disconnecting the negative battery post, the relay coils drop out because you disconnect the circuit? --- The positive cable might be different. --- Personally, I would NEVER try either of these on any car with a computer!

By the way, good answer about the flooded car on a different thread.
Busted_PT likes this.
Reply With Quote
  #6 (permalink)  
Old 25 Jul 2013, 06:21 am
Busted_PT's Avatar
Obsessed Cruiser
 
Join Date: Jan 2012
Location: Beckley, W.V.
Posts: 13,882
Default Re: Old test for bad alternator no longer a guarantee!

Quote:
Originally Posted by pt06 View Post
Busted; in the old days the alternator only needed a regulator [usually mounted on the firewall on mopars] to make electricity. The regulator only needed power from the ignition switch to work. Since there was no other electronics involved [like pcm's] , your test was valid to find out if the alternator put out at least some electricity.

Just a theory: by disconnecting the negative battery post, the relay coils drop out because you disconnect the circuit? --- The positive cable might be different. --- Personally, I would NEVER try either of these on any car with a computer!

By the way, good answer about the flooded car on a different thread.
Was indeed the pos. I pulled off. Will try the neg. to see if any difference. I never put the cables back on with the key on or running. To minimize the risk if any. Still curious why rob342 was able to keep his running.
rob342 likes this.
__________________

03 Dream stock___________________________ 04 Touring turbo lite stock_________ 02 Touring stock_____________________ The "Three Amigos"
__________________________________________________ __________________________________________________ ___________Performance, Body and Service, OEM

This Is my project page.
http://www.ptcruiserlinks.com/forum/...oject-1-a.html

This is a great read from one of our own! Badglas
badglas.blogspot.com

Last edited by Busted_PT; 25 Jul 2013 at 07:16 pm.
Reply With Quote
  #7 (permalink)  
Old 25 Jul 2013, 06:48 am
Fanatic Cruiser
 
Join Date: Jun 2009
Location: Rochester, Michigan
Posts: 669
Default Re: Old test for bad alternator no longer a guarantee!

Do not disconnect the battery with the engine running...doing so can cause high voltage transient spikes that may damage electronics...you might get away with it but then again you might not...you are relying on how good the "load dump" protection built into the various chips and circuitry. Another issue is the fact that modern computer controlled voltage regulation schemes monitor the differential between the battery and alternator output and adjust alternator output accordingly...without total familiarity with the system in your vehicle you won't know what to look for in terms of a default voltage (if any). There are multiple charging schemes in use between GM, Ford, Chrysler and they have their differences. It's not your father's Oldsmobile any more.
Chip18sw likes this.

Last edited by Carl48; 25 Jul 2013 at 11:42 am. Reason: spelling
Reply With Quote
  #8 (permalink)  
Old 25 Jul 2013, 07:42 am
Fanatic Cruiser
 
Join Date: Sep 2012
Location: Carson City NV
Posts: 675
Default Re: Old test for bad alternator no longer a guarantee!

Quote:
Originally Posted by Carl48 View Post
Do not disconnect the battery with the engine running...doing so can cause high voltage transient spikes that may damage electronics...you might get away with it but then again you might not...you are relying on how good the "load dump" protection built into the various chips and circuitry. Another issue is the fact that modern computer controlled voltage regulation schemes monitor the differential betwen the battery and alternator output and adjust alternator output accordingly...without total familiarity with the system in your vehicle you won't know what to look for in terms of a default voltage (if any). There are multiple charging schemes in use between GM, Ford, Chrysler and they have their differences. It's not your father's Oldsmobile any more.
What he said! That cable pulling is old school and kind questionable back then! Certainly not a good idea on any car with a computer!...regardless of the PT's retro look!
Reply With Quote
  #9 (permalink)  
Old 25 Jul 2013, 04:39 pm
Veteran Cruiser
 
Join Date: Mar 2012
Location: darien il
Posts: 4,592
Default Re: Old test for bad alternator no longer a guarantee!

Quote:
Originally Posted by Busted_PT View Post
Still curious who rob342 was able to keep his running.
yeah me too. i removed the battery and my car didn't die until i had it completely installed in my friends vehicle. i did have the radio, blower, and all that turned off. i figured it probably died because it got jealous. it wanted its battery back. it knew how to get its way.
Busted_PT likes this.

Last edited by rob342; 25 Jul 2013 at 05:04 pm. Reason: honestly, i think it died because the cooliing fan kicked on and pulled more juice
Reply With Quote
  #10 (permalink)  
Old 25 Jul 2013, 05:02 pm
Veteran Cruiser
 
Join Date: Mar 2012
Location: darien il
Posts: 4,592
Default Re: Old test for bad alternator no longer a guarantee!

Quote:
Originally Posted by Busted_PT View Post
Tried it today and my 03 died straight away.
yeah, i think you just got crappy alternators man.

maybe i beat it into submission. maybe my car just likes me. maybe MY PT is just a liiiiiittttle bit better than the rest of the PT's in the world. like the Sonny in the movie IRobot. it's better than the rest, has the ability to think for itself, to make decisions. maybe it's made with harder alloy, because it's creator gave it a purpose.

here's a video i JUST took. you know, just because..



-and yes i understand the risks in doing this. it isn't a habit of mine. i know curiosity killed the cat. you can call me curiosity. and maaaaan am i gonna feel dumb if my car breaks down on the way home now.
Busted_PT likes this.

Last edited by rob342; 25 Jul 2013 at 05:31 pm.
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Longer oil filter for 2.4L NA jwv3 Tech & Performance Forum 10 23 Nov 2012 06:39 pm
Alternator test?? CUBANO General PT Cruiser Discussions 1 21 Apr 2009 08:36 am
I can't wait any longer careyk General PT Cruiser Discussions 1 05 Apr 2009 01:59 pm
Chrysler Gas Price Guarantee Incentive: Let's Refuel America skylight PT Cruiser News and Rumors 4 31 Jul 2008 02:29 pm
Chrysler Extends Gas Guarantee For 2nd Month skylight PT Cruiser News and Rumors 1 29 May 2008 08:20 am


All times are GMT -5. The time now is 10:22 am.




Powered by vBulletin® Version 3.8.2
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
LinkBacks Enabled by vBSEO 3.6.0 PL2 © 2011, Crawlability, Inc.
vB.Sponsors