At a loss replaced alternator and its still not charging the battery

Reply Subscribe

Thread Tools

Search this Thread

Apr 26, 2006 | 11:55 AM

RemoTT

Thread Starter

AudiWorld Member

Joined: Feb 2005

Posts: 312

Likes: 0

At a loss replaced alternator and its still not charging the battery

does anyone have the wiring diagram from the alternator to the battery and or the charging system. The new was verified to be good. Anyone have any ideas...........

Apr 26, 2006 | 12:25 PM

MCPaudiTT - DEFCON 1

AudiWorld Super User

Joined: Nov 2004

Posts: 10,902

Likes: 3

The battery is good? Even new ones can be bad - did you try a known good one?

Apr 26, 2006 | 12:28 PM

TTschwing

AudiWorld Uber User

Joined: Dec 2000

Posts: 53,281

Likes: 2

Did you do the voltage checks that I posted yesterday?

Apr 26, 2006 | 12:33 PM

RemoTT

Thread Starter

AudiWorld Member

Joined: Feb 2005

Posts: 312

Likes: 0

Battery is good its not being charged, a possible broken lead between

the alternator and the battery or charging system..........

Apr 26, 2006 | 12:34 PM

RemoTT

Thread Starter

AudiWorld Member

Joined: Feb 2005

Posts: 312

Likes: 0

Yes never got above 12.5 and started going down

Apr 26, 2006 | 01:09 PM

TTschwing

AudiWorld Uber User

Joined: Dec 2000

Posts: 53,281

Likes: 2

Are you sure the new one is good then?

Apr 26, 2006 | 01:43 PM

Rocky-in-Connecticut

AudiWorld Super User

Joined: Mar 2005

Posts: 11,616

Likes: 2

proper charge diag

1. load test battery - it is not enough to simply measure static voltage of a battery. A battery that says 12.5v just sitting there can fall on its face under a real load test.

A BAD BATTERY CAN THROW OFF ALL OTHER CHARGE TESTS

2. check charge voltage across the battery engine running (rev engine too).

3. check voltage drop alt (+) to battery (+)
wiggle test cable as well

4. check voltage drop (-) battery to ground
wiggle negative cable as well.

Alternator cable failure is rare (so is alternator failure). The battery is usually the culprit in these cars.