|
Welcome to the Australian Ford Forums forum. You are currently viewing our boards as a guest which gives you limited access to view most discussions and inserts advertising. By joining our free community you will have access to post topics, communicate privately with other members, respond to polls, upload content and access many other special features without post based advertising banners. Registration is simple and absolutely free so please, join our community today! If you have any problems with the registration process or your account login, please contact us. Please Note: All new registrations go through a manual approval queue to keep spammers out. This is checked twice each day so there will be a delay before your registration is activated. |
|
The Pub For General Automotive Related Talk |
|
Thread Tools | Display Modes |
|
05-11-2009, 11:14 PM | #1 | ||
Banned
Join Date: Aug 2009
Posts: 382
|
What should the voltage across the battery terminals read on a brand new battery installed into a car? Is it meant to begin at the battery's current off-the-shelf voltage (12.5) and as it charges, climb up until it matches the car's electrical system (13.8)? These measurements are made when engine is running btw.
I've just installed a new battery, and the voltage at the terminals with engine on, began at 12.5. After a short 5 minute drive, it was climbing towards 12.8. Shouldn't the voltage at terminals be already at around 14v, as soon as a new battery is installed and engine is turned on, or is everything ok? From inside the car (cig lighter socket), there's a healthy 13.8v however, regardless of what the battery terminals are at. Last edited by barra265t; 05-11-2009 at 11:23 PM. |
||
05-11-2009, 11:18 PM | #2 | ||
Now Fordless
Join Date: Aug 2005
Location: Fremantle, WA
Posts: 3,611
|
Yep. Will be around 12.5 when car is not running. Around 14 when running.
|
||
05-11-2009, 11:38 PM | #3 | ||
Now Fordless
Join Date: Aug 2005
Location: Fremantle, WA
Posts: 3,611
|
It should read 14 almost straight away. Try putting the lead of the multimeter on the positive on the back of the alternator and see whats coming out of there.
|
||
06-11-2009, 12:09 AM | #4 | |||
Banned
Join Date: Aug 2009
Posts: 382
|
Quote:
|
|||
06-11-2009, 12:51 AM | #5 | ||
FF.Com.Au Hardcore
Join Date: Jun 2007
Location: republic of wa
Posts: 869
|
gday all . had this problem a few years back. turned out to be corroded connection on the alt. (main power feed to the battery). also the little wire going to the warning light was a bit loose. should read about 12.5 car off, 14.6 car running
|
||
06-11-2009, 01:09 AM | #6 | ||
Now Fordless
Join Date: Aug 2005
Location: Fremantle, WA
Posts: 3,611
|
This pic is not of a Falcon its just an example.
The positive going to the battery is a thickish wire usually held on by a nut as in photo and covered by a rubber boot. Will be on the back of the alternator. If its accessible,(im not sure I cant remember on these engines) you can put the positive side of the multimeter on this to check if the alternator is putting out any voltage. Warning - if this is attempted, make sure you dont touch any other metal and arc out the alterator. Will blow fuses |
||
06-11-2009, 10:57 PM | #7 | |||
FF.Com.Au Hardcore
Join Date: Jan 2005
Posts: 1,463
|
Quote:
|
|||
Thread Tools | |
Display Modes | |
|