Electrical question - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars
 
LinkBack Thread Tools Display Modes
post #1 of 8 (permalink) Old 06-02-02, 05:08 AM Thread Starter
Ex Member
 
Fairlane Boy's Avatar
 
Join Date: Nov 2001
Location: Perth
Posts: 717
Electrical question

How do you tell if your alternator is shagged or your battery?

my "other" car just wont even try turning over by the power of its own battery, it needs jumping everytime now.

at idle the voltage is @ 12.5 but at about 100rpms higher than idle or more its up at 13.5-14V at the battery.

the alternator is 31 years old and is OEM, never rebuilt.


Best wishes
Fairlane Boy is offline  
Sponsored Links
Advertisement
 
post #2 of 8 (permalink) Old 06-02-02, 05:19 AM
Australian ED Fairmont Member
 
Join Date: Nov 2001
Location: Gisborne, Victoria, Australia
Posts: 34
Your alternator must be working O.K. if you have about 14 volts output. Looks like you need a new battery.
lsd0 is offline  
post #3 of 8 (permalink) Old 06-02-02, 05:24 AM Thread Starter
Ex Member
 
Fairlane Boy's Avatar
 
Join Date: Nov 2001
Location: Perth
Posts: 717
thanks

Best wishes
Fairlane Boy is offline  
post #4 of 8 (permalink) Old 06-02-02, 10:19 PM
Officially Bored with 347
 
svo347's Avatar
 
Join Date: Jul 2001
Location: Perth West Oz
Age: 43
Posts: 3,585
I think you'll find it should be around 14v at any RPM... Try turning your headlights on 7 see if its still 14v If its not its cactus mate as it should still pump out 14v+ under any load..
Cheers

FORD.... "POWER TO THE PEOPLE"...

Member of the "TKTDSGM " Group..
svo347 is offline  
post #5 of 8 (permalink) Old 06-03-02, 12:46 AM
Australian EL Wagon Member
 
dcstraight's Avatar
 
Join Date: Oct 2001
Location: Melbourne
Age: 37
Posts: 677
Quote:
Originally posted by svo302
I think you'll find it should be around 14v at any RPM... Try turning your headlights on 7 see if its still 14v If its not its cactus mate as it should still pump out 14v+ under any load..
Cheers
All things being equal - yeah it should pump out 14V, unless you've got an audio system which can also cause voltage drops. Either way, it sounds damn old - might perhaps pay to have it rewound, if you have further problems. If it is a battery, and you don't mind spending a bit (and if you're pedantic like me) look at a dry cell like an Optima yellow top or Odysey (SP?). Anywho, just my 2c.

Cheers,
Steve

Wagons are rarer ;-)
dcstraight is offline  
post #6 of 8 (permalink) Old 06-03-02, 03:50 AM Thread Starter
Ex Member
 
Fairlane Boy's Avatar
 
Join Date: Nov 2001
Location: Perth
Posts: 717
Quote:
Originally posted by dcstraight


All things being equal - yeah it should pump out 14V, unless you've got an audio system which can also cause voltage drops. Either way, it sounds damn old - might perhaps pay to have it rewound, if you have further problems. If it is a battery, and you don't mind spending a bit (and if you're pedantic like me) look at a dry cell like an Optima yellow top or Odysey (SP?). Anywho, just my 2c.

Cheers,
Steve
the engines running like shyte at the moment, idling so slow its barley even running. it gets to 14v when its at the speed its ment to be idling at. Its not going anywhere till its got its new floor, new paint & new leather. I wonder how to rebuild a twin carby setup.....

Best wishes
Fairlane Boy is offline  
post #7 of 8 (permalink) Old 06-03-02, 03:12 PM
Registered User
 
Join Date: May 2002
Location: Canberra
Posts: 12
Alternators need the motor to be running at about 1000 RPM for their maximum (best & efficiet) output, & it shouyld be around the 14V mark (13.8V is optimal). It sounds like your alternator is working fine.

To check the battery, put it on a charger over night. Then check each cell with an acid level meter (I don't know it's correct name. Its a glass tube with a float inside it with a rubber bulb on the top). Each cell of the bettery should come up to the same float level, ideally in the green band on the float.
LTD4Me is offline  
post #8 of 8 (permalink) Old 06-03-02, 05:22 PM
Officially Bored with 347
 
svo347's Avatar
 
Join Date: Jul 2001
Location: Perth West Oz
Age: 43
Posts: 3,585
Hydrometer... measures the specific gravity of each cell

FORD.... "POWER TO THE PEOPLE"...

Member of the "TKTDSGM " Group..
svo347 is offline  
Sponsored Links
Advertisement
 
Reply

  Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars > The Garage - Tech Forums > Interior | Electrical | ECU


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Electrical question --> Battery Fairlane Boy Interior | Electrical | ECU 5 03-10-03 09:22 AM
NA LPG Question, EA dash question Troutman LPG Tech 3 07-23-02 07:17 AM
NAPARM- Thread Preview Question batbo6 The Pub 5 07-23-02 02:58 AM
Job application question: HSE2 The Pub 8 05-06-02 12:12 AM

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