Alternator/charging problems

  1. Established Member Joined: Mar 2010 Basildon, Essex Posts: 1042 Citroen AX VTS
    #1
    So the saga goes;

    Took the ax for MOT and conked out twice, had to jump it twice to get it home

    Decided to buy a new battery as the old one was old and a bit fucked, gone flat too many times

    Hooked it up and found I was only getting 12 volts with the engine running, which pointed to an alternator issue. Was also only getting 12 volts at the alternator which rules out a resistance issue in the wiring

    I got another second hand alternator and installed it, and still only 12 volts at the battery and the alternator.

    My battery is installed in the boot, then I have a wire going to under the dash, which splits off to the starter and the fuse box. I've checked and there's good continuity in the wire from the alternator to the starter. The alternator is also earthing well to the block.

    I tried revving the engine while monitoring the alternator output and it doesn't change

    I literally have no idea what else it could be! Help pleeeeeease
  2. Saxperience Hardcore! Joined: Oct 2008 Birtley Posts: 22253 VTR Turbo, 106 xsi track slag, Transit recovery, B
    #2
    Shouldn't really split it,

    Should run a wire from fuse box to terminal on starter, same for live.. Direct to starter doubt that will make any diff like lol

    I'd say try someone else's alternator first as you may have bought a dodgy one lol
  3. Frequent Poster Joined: Dec 2010 coalville Posts: 711 project flat arch
    #3
    The alternator has a regualtor , this puts more load on the alternator when things like your lights or wipers or music is on. So the more u have switched on the more load so u can get up to like 14 volts to charge the battery. So might just be the regulator on the back. Also check the regulator wire on the alternator.
  4. Established Member Joined: Mar 2010 Basildon, Essex Posts: 1042 Citroen AX VTS
    #4
    Tbh it should still show 14 volts on idle even with nothing on

    Gonna disconnect the alt wire and run a temp wire straight from alt to battery to rule out the wiring as a problem. Reckon you're probably right though blackie, it's the only thing left other than a dodgy alt but that was working when removed from the previous vehicle
    1 user thanked this post:
  5. Saxperience Hardcore! Joined: Oct 2008 Birtley Posts: 22253 VTR Turbo, 106 xsi track slag, Transit recovery, B
    #5
    its happend to me before mate.... ive just put another engine in my R and for 3 weeks ive traced wires as it wouldnt start off the key...only bump or jump off a good battery but not starter pack..i eventually thought fuck it ill change the starter and it fired straight up lol

    and yeah if the egines running it should show 14
  6. Established Member Joined: Mar 2010 Basildon, Essex Posts: 1042 Citroen AX VTS
    #6
    Top tip for fault finding - do one thing at a time

    The other day I sorted some issues with the alternator not earthing to the block due to having powdercoated brackets, Presumably that solved the problem, however I fitted the new alternator at the same time, which is duff!!

    Put old alternator back in and it was charging at 13 volts, gradually rising (think the battery is a little flat due to starting it up so much over the last few days).

    So yeah, fixed!! Gonna replace the wire from the alternator to the starter anyway as it looks a bit rough. And yeah it's working with the wiring split under the dash. I bypassed this to see if it was better with more straight forward wiring but it was the same so left it as it is as its neat
  7. Saxperience Post Whore Joined: Jan 2007 Shropshire Posts: 9994 Moonstone Blue 106 GTi
    #7
    owe you a pint and hug then at dt
    1 user thanked this post:
  8. Established Member Joined: Mar 2010 Basildon, Essex Posts: 1042 Citroen AX VTS
    #8
    Ha no worries Gav, to be fair it was only the alternator that I gave you from Tom's GTi so who was to know it wouldnt work! All is well for MOT now woop woop