XJS ( X27 ) 1975 - 1996 3.6 4.0 5.3 6.0

Testing Alternator on 1996 V12 6 Litre

Old Aug 27, 2025 | 03:38 PM
  #1  
ptjs1's Avatar
Thread Starter
|
Veteran Member
10 Year Member
Liked
Loved
Community Favorite
Joined: Apr 2014
Posts: 4,580
Likes: 3,528
From: Kent, UK
Default Testing Alternator on 1996 V12 6 Litre

Having now got my friends 1996 6 litre running, it seems that the alternator isn't working. I'm not entirely sure when the engine had last been run, but it could be a few years ago.

The voltmeter gauge reads just about 12v with the engine running. Of course, we can't trust the gauge, but a voltage reading on the battery with a multimeter shows just 12.1v with engine running (battery fully charged prior to starting). The belt is properly tensioned and the pully is turning.

Bearing in mind the limited access, what's the best way for me to test for voltage output from the alternator? (other than just putting a voltmeter across the battery with the engine running). I can only find an ammeter with a max 10a, so can I also test for amps or will I damage the meter? Where's the best place to test amp reading? Ideally near the alternator as opposed to connecting at the battery? Is access at the alternator practical without dismantling stuff?

Any suggestions gratefully received!

Paul
 
Reply
Old Aug 27, 2025 | 05:28 PM
  #2  
AZDoug's Avatar
Senior Member
Liked
Joined: Sep 2023
Posts: 445
Likes: 239
From: Central Arizona
Default

Alt should put out 14-16V. Amps don't matter if all you are getting is 12V, thats just reading the battery.

Local auto parts can usually check the alt for free, at least across the pond from you. Call around in your area

Doug
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Pabarlow
XJS ( X27 )
3
Nov 16, 2024 11:30 PM
1996vdp
XJ XJ6 / XJR6 ( X300 )
12
Mar 11, 2022 10:07 PM
51rover
XJS ( X27 )
10
Oct 5, 2021 02:16 PM
nurquhar
XJ XJ8 / XJR ( X308 )
10
Oct 6, 2018 09:36 AM
mikebaker3
XJS ( X27 )
2
Jan 27, 2014 11:35 AM

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

Thread Tools
Search this Thread

All times are GMT -5. The time now is 05:18 PM.