246GT Electrical Charging Aberrancy | FerrariChat

246GT Electrical Charging Aberrancy

Discussion in 'Technical Q&A' started by jselevan, Jan 26, 2004.

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  1. jselevan

    jselevan Formula 3

    Nov 2, 2003
    The continuing saga:

    I changed the ignition switch. Right. No problem.

    The battery goes dead, ampere meter reveals discharge - no charging of the battery. I have rebuilt the alternator 6 months ago for similar symptom. Seldom drive the car.

    I change the regulator, put in a generic Fiat device with same 3 leads (+, -, field). Works like a charm, for a while.

    Now the symptom is exactly as before - when starting cold, will discharge as though their is no alternator belt. After approximately 5 minutes of running, the ampere meter swings positive and works precisely as it should. Charges at 40 amperes for a few moments, and then slowly comes down to 0 ampere flow while driving. At idle it discharges, and once above 12-1500 RPM, charging like it should.

    Question: What is happening during the first 5-10 minutes of running that prevents the alternator-regulator from charging the battery?

    Has anyone experienced this?

    Jim S.
  2. Michael Aguilar

    Nov 28, 2003

    Sounds like it's an alternator problem , most likely the voltage regulator.
    I had an overcharging problem on my 246 GTS few years ago so what i had done is install an external voltage regulator , I used a ford electronic type. Since then never had a problem.

  3. T.O. Dino

    T.O. Dino Formula Junior

    Oct 30, 2004
    Toronto Canada
    I would be interested in finding out which regulator you used and if it was a staight forward swap. My 246 is also overcharging at about 17.0v @4000rpm, then drops to a negative charge 11v at idle. Less if there is any type of load. I have changed the regulator for a new one but the problem is still there.

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