Thread Rating:
  • 18 Vote(s) - 2.72 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Alternator not charging no 12v at small purple wire
#1
Hi all,

We have just fitted a new alternator to my son's 2005 2.0 HDi and it is not charging as we are only getting 10.5v at the battery with the engine running.

I have read of a similar issue on a Peugeot forum and that there should be 12v at the small purple/violet wire when the ignition is switched on but there is no power there and unfortunately the thread tails off with no conclusion.

If I connect a 12v feed directly from the battery to where the small wire plugs into the alternator with the engine running we get a healthy 14.5v at the battery.

On the basis of the above I have assumed that the battery and new alternator are ok but there must be a problem with a fuse, relay or wiring feeding the switched circuit to the purple wire.

Can anyone suggest a solution as we have tested all the fuses in the engine compartment and inside.

Many thanks in advance for any suggestions.

Kind Regards

Peter
Reply
#2
The alternator needs 12v to make it work.
This is usually supplied through the ignition switch. Faulty ignition switch ?
[-] The following 1 user says Thank You to brodfather11 for this post:
  • td5
Reply
#3
Hi, This "excitation voltage" is produced from the Bsi and connects to the alternator through the engine bay fuse box.
Check all engine bay fuse connections and also the Bsi connections.
"EP" connector especially. You are looking for water damage from the windscreen leaking etc or corroded connections.
(The Bsi is the fuse box under the steering wheel).
:thumbsup:
2006 2.0hdi 600 with bench seat.  Cool
[-] The following 1 user says Thank You to Rustscrat for this post:
  • td5
Reply
#4
Thank you both for the above suggestions and I can now confirm that the problem has been resolved.

It turned out that the new alternator I purchased was indeed faulty even though it appeared to charge correctly when supplied with a 12v feed directly. The explanation I was given was that on startup the alternator sends a pulse to the BSI which in turn supplies a 12v feed back to the alternator down the purple wire. No pulse was being sent so no feed was provided.

The alternator I purchased was an RTX make supplied by EuroCarParts whom I have been quite happy with in the past however when subsequently googling RTX alternators there do seem to be some mixed opinions/experiences from people.

So in hindsight my £90 alternator ended up costing me a further £330 (Another new 'decent quality' alternator plus second lot of labour to run diagnosis and swap units out)

Hope this helps anyone else in the same predicament.

ATB

Peter
[-] The following 4 users say Thank You to td5 for this post:
  • Husqyman, Ol'Jeffers, ron, Rustscrat
Reply


Forum Jump:


Users browsing this thread: 1 Guest(s)
[-]
Welcome
You have to register before you can post on our site.

Username:
  

Password:
  




[-]
Search
(Advanced Search)

[-]
Latest Threads
new mot
Last Post: Oi69
Yesterday 09:56 PM
» Replies: 9
» Views: 719
Dingo - 05 - 2.0 HDI
Last Post: jj9
Yesterday 09:53 PM
» Replies: 63
» Views: 11220
Rear door
Last Post: Gravity
Yesterday 07:28 PM
» Replies: 3
» Views: 516
Cruise control (again), yes again, but working (...
Last Post: Collapsedsuspension
Yesterday 10:09 AM
» Replies: 96
» Views: 7470
Heater problems
Last Post: Fuseman
20-05-2018 08:34 PM
» Replies: 2
» Views: 308
Grizz' Prozac for the Soul - Berlingo Multispace
Last Post: Grizz
20-05-2018 08:21 PM
» Replies: 312
» Views: 34388
side loading handle
Last Post: Hung2hi
19-05-2018 02:57 PM
» Replies: 9
» Views: 1131
exhaust
Last Post: Hung2hi
19-05-2018 02:45 PM
» Replies: 10
» Views: 941
Fuel Expansion Tank
Last Post: Collapsedsuspension
19-05-2018 08:17 AM
» Replies: 4
» Views: 512
DAB reception since TV retune on thursday
Last Post: kenny70
19-05-2018 07:11 AM
» Replies: 8
» Views: 1029

[-]
Recent Visitors
Locations of visitors to this page