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Mondial 3.2 alternator upgrade...suggestions?

Discussion in 'Technical Q&A' started by Robin Wells, Sep 28, 2004.

  1. Robin Wells

    Robin Wells Rookie

    Aug 26, 2003
    29
    Dubai, United Arab E
    Full Name:
    Robin Wells
    Here's one for Mondial owners with some experience of electrical gremlins....in other words, all of us!

    My local servicing agent has traced an electrical problem back to the alternator, and I am not entirely sure if this is correct or not. I have checked the archives, old and new, and can't find anything that directly relates to this, so here goes:

    The car is a 3.2 Mondial Cab, 1986 model. I imported it from Italy to Dubai last year and it's in good condition, with major service done 5k ago.

    The alternator is, in fact, fine. I took it to the Bosch service centre, they put it up on the testing rig and it is putting out 80-85A at rpm 3,500. Voltage is 13.5V - this all seemed fine to them and they gave it a clean bill of health.

    The service agents are saying that, because it is so hot here (never less than 23 degrees, upto 45 in summer), the AC is on max all the time and the engine fans are always on, so there is a large draw of current and maybe the alternator's output isn't sufficient (at 80-85A) to support these accessories and re-charge the battery. So, they suggest that, instead of putting this one back in the car, I consider upgrading the output to 120A.

    I'm not entirely convinced, because:
    - never heard of this with other Mondials
    - while it is hot here in summer, Italy can be too! and surely if Ferrari build a car with AC and engine fans, the elec system can support it (or maybe not)
    - never entirely convinced of local diagnostic procedure.

    For info, our journeys in the car are usually at least 40 minutes every weekend, minimum. We spend a lot of the time above 3,500 rpm so I don't think excessive idling is a problem.

    Any thoughts would be much appreciated.

    Btw, thanks to Tom B for introduction to Dean Romer at Wide World of Cars, who sent plastic block connectors for burnt fuse box back in May.

    Robin Wells
    Dubai, United Arab Emirates
     
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  3. TOM B

    TOM B Formula 3

    Jul 24, 2003
    1,038
    Orange County, NY
    Full Name:
    Thomas Buckley


    My Pleasure Robin. I'm glad it worked out. Please keep us posted on the ongoing story.
     
  4. f355spider

    f355spider F1 World Champ
    Rossa Subscribed Owner

    May 29, 2001
    17,577
    USA
    I would agree that the diagnosis may be wrong...what are the symptoms you are experiencing that is leading them to think you need a higher output alternator?
     
  5. atlantaman

    atlantaman Formula 3

    Mar 31, 2002
    1,726
    Roswell, Georgia
    Full Name:
    Charles
    I had the "core" on my 328 unit swapped out with that of a Mercedes and now have a nice 110amp unit
     
  6. Robin Wells

    Robin Wells Rookie

    Aug 26, 2003
    29
    Dubai, United Arab E
    Full Name:
    Robin Wells
    Dave

    The symptoms were that the car didn't start!

    One day, after a good journey, I turned the ign switch and nothing. No dash lights, no cranking, nothing. Thinking I had maybe just not turned the key correctly, I did it again and it starts no problem.

    Conclusion - short term memory loss or intermittment ign sw fault.

    Then next weekend, I go to start the car and had the same symptoms - only this time, it continued to remain dead.

    I had other stuff to fix and I was working on replacing the fuse board, so this fault kind-of merged into another....not very helpful for diagnosis I know!

    Having replaced the battery with a charged one as part of the on-going fault-finding, the accessories were working OK, radio lights etc, but there was no cranking - nothing at all. So I took it into the garage suspecting an ignition switch fault.

    Having done their diagnosis, they are saying that the ignition sw is fine, but the problem is that there is simply too much drain on the elec system because I have so much elec stuff runinng at the same time (all standard I must add, no big sound system) - and therefore they recommend I replace the standard 85A alternator with an upgraded one.

    Yes...OK... I can understand their logic, but is this really the problem? I'm thinking I'll just put the stock alternator back in, and then put the car on a trickle charger overnight instead.

    What do you think?
     
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  8. Robin Wells

    Robin Wells Rookie

    Aug 26, 2003
    29
    Dubai, United Arab E
    Full Name:
    Robin Wells
    Just looked at the handbook of my SAAB 93, my regular car, to get a different perspective.

    For models fitted without AC (northern Europe, I presume), the alternator is 80A.

    For those models fitted with AC (definitely us in the Middle East), the alternator is a massive 130A.

    What a difference. Does the Air Con really consume that much power?

    So, for those who have done this upgrade on 328/3.2 Mondials (atlantaman) where should I start? No-one I spoke to here seemed interested/capable of doing the re-wiring job, so any recommendations from places in the US/Europe who could ship something out to the Middle East - maybe just an upgraded core if the whole frame is too heavy?

    In the meantime, I've asked the garage to put the stock alternator back on and will simply hook it up to a trickle-charger over night. And get my wife to fan me whilst I drive.
     
  9. f355spider

    f355spider F1 World Champ
    Rossa Subscribed Owner

    May 29, 2001
    17,577
    USA
    I assume the battery has been load tested, but I might consider replacing it anyway....
     
  10. Steve King

    Steve King F1 Rookie

    Feb 15, 2001
    4,366
    NY
    Sounds like you have a short somewhere that is draining the battery. Also you need to check the main wire from the battery to the starter. If you have power to the lights and gages and when you try to start the car none of these dim then it is a problem with the starter relay or the starter itself. Hard to diag. like this.
     
  11. Mark 328

    Mark 328 Formula Junior

    Nov 6, 2003
    510
    Orange, Ca
    Full Name:
    Mark Foley
    Atlantaman:

    I would be interested in that MBZ conversion for the 328; Do you know any secifics about the MBZ alternator? P/N, model, or year of car, also could the guts of the MBZ alternator fit into the 328 case?

    It would be good to do this to my 328--you never know when you may have to arc weld something on the side of the road :)

    Any info would be appreciated.

    Mark
     
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