would i be right in saying my alternator is fubared?

Discussion in 'Motorhome Chat' started by Emmenay, Sep 1, 2012.

  1. Emmenay

    Emmenay Read Only Funster

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    On a journey to Spain very recently I noticed that the habitation batteries and the engine battery were reading less than usual voltage on the control panel after every journey whether it had done 10 miles or 400 miles. The most it was reading was 12.4 volts when settled. Previously it has measured a comfortable 12.8v so I put it down to lots of air con etc. throughout spain.

    Now that I have returned home I have been able to show it the voltmeter this morning, (should have taken it with me I know :Doh:). What I have found is this;

    The engine battery voltage at rest was 12.5 volts, as were both the hab batteries. Once started, the engine battery was reading 14.4v, with the hab batteries reading 13.4v after a little while.

    Now the interesting bit, I turned the air con on which was usual in spain, then the hadlamps and wipers, the voltage dropped to 12.6v and very slowly kept dropping until it got to 12.4v, at which point I got fed up!

    Now I must point out that all of my batteries are new this year so I think I can eliminate them, and this has been the first time I have needed the air con for any distance as well as frequent use of headlamps for evening driving.

    Does this sound like the alternator is on its last legs or am I barking up the wrong tree?
     
  2. CHRI$

    CHRI$ Funster

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    no it sounds like your alternator is not man enough:Smile:
     
    Last edited: Sep 1, 2012
  3. pappajohn

    pappajohn Funster Life Member

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    I agree with Chris.

    if your alternater is chucking out 14.4v its trying its best to keep on top of battery drain but cant quite manage the amps needed.

    high output alternator needed.....or dont use the air-con.
     
  4. Emmenay

    Emmenay Read Only Funster

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    Thanks for the prompt reply chris, it does seem like the alternator but it pays to get second opinions :thumb:
     
  5. Emmenay

    Emmenay Read Only Funster

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    Update - Good news

    This morning I had my alternator removed due to the charging issues. It turned out that it was only 90amps so nowhere near enough to do everything expected of it.

    I now have a 120amp unit fitted and what a difference, all three batteries are receiving a healthy 14v charge with 13.8v being reached with everything switched on (as opposed to the recent 12.4), its not only a higher charge but seems to be a much deeper charge (if thats possible) as the voltage is taking forever to find its dormant level so to speak when the engine is turned off.

    I can rest easy now that the hab batteries should last a lot longer and the engine will start in the morning!

    So far that is the best few quid I have invested on the MH.:thumb:
     
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  6. Popeye

    Popeye Funster

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    Well if ever there was a prime example of MHFun fee of £10 being recouped several times over this is one hell of a good one.

    Well done Chris, Pappajohn and Emmenay for asking . .:thumb:
     
  7. Emmenay

    Emmenay Read Only Funster

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    Couldn't agree more, It seems whenever I need to spend money on the bus i just do my homework on here and its money saved everytime thanks to the knowledgable folk on here (you all know who you are:Blush:)
     
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