Alternator questions | FerrariChat

Alternator questions

Discussion in '365 GT4 2+2/400/412' started by SouthJersey400i, Aug 27, 2008.

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  1. SouthJersey400i

    SouthJersey400i Formula 3

    Mar 14, 2007
    1,679
    Romulus, NY (Finger Lakes)
    Full Name:
    Ken Battle
    I had this post all written and was checking it and hit the wrong button and my long-winded description vanished into electron heaven. So I will give a more abbreviated version this time.

    I recently have had starting issues both after driving for a fair distance with the AC on and also after leaving the car sit for as short as a day. I have proven it is not the starter motor as a quick charge gets it going. Battery is large and new and it does not fit the pattern. I checked for amp drain while idle which I had 18 months ago when I bought the car and I do not have that problem now. I checked the charging and here is where the issue seems to be. I get about 12.8 V at idle and 13.6V at 2000 RPM or higher. When I bought the car I checked and had 13.6 at idle and 14+ at 1500 RPM or higher. So I suspect one or both alternators are weak or not functioning.

    Here are my questions:
    1. What is best procedure to check each alternator? Remove one belt? Remove all wires from one unit? I know it is possible to ruin a good alternator by pulling wires while motor is running but I think there should be a way to check each one with motor running.

    2. Let's say I identify one bad alternator, what is the origin of these units? Are both identical? Does anyone know a shop to rebuild them in a timely manner in the Northeast US? Can they be bought outright at a reasonable price? If they are of common origin, I have a local shop that does good work and I will tell him it is from a Fiat to keep the cost down.

    I look forward to some quick replies as I want to sort out this weekend because I have an F-club event the following weekend.
    Ken
     
  2. Ak Jim

    Ak Jim F1 Veteran
    Owner Rossa Subscribed

    Dec 23, 2007
    9,623
    North Pole AK
    Most places that rebuild alternators can also check them. The only problem is you have to take them off of the car. One thing to remember is if one is bad the other is most likely the same age!
     
  3. blkprlz

    blkprlz Formula 3

    Mar 24, 2007
    2,169
    Tampa bay
    Full Name:
    Bruce
    Ken, I'm away from home traveling so can't check parts manual but Eurospares shows both alt's have same part #......
    http://www.eurospares.co.uk/partTable.asp?M=1&Mo=652&A=1&B=37716&S=

    My alt's were rebuilt years ago when the previous owner (Wil) owned it & Peter from Forza MS knew Wil pretty well, he should be able to direct you; for that matter, Bill Pollard could as well.....
    Peter @ Forza, 3 Martha Lane Gaylordsville CT 06755. 860-350-1140 fax:860-350-1148 Email: FORZAMOT@aol.
    Bill @ Sportauto, 25 Martha Ln, Gaylordsville, CT. Tel: 860-350-1515
    IIRC, they weren't tremendously expensive to rebuild, but not inexpensive either. While your at it, you might as well pull both for rebuild as mentioned by AK Jim. Pull the left tire to make access easier for the lower unit, but it's more involved than the upper. There's a steering component that has to be disassembled to remove the long mount'g bolt.
    Eurospares shows the price for new alt's @ $22.20 pds. ea., that can't be correct!!!
    HAHAHA, you're killing me on the Fiat note......funny & smart! Bruce
     
  4. SouthJersey400i

    SouthJersey400i Formula 3

    Mar 14, 2007
    1,679
    Romulus, NY (Finger Lakes)
    Full Name:
    Ken Battle
    I have still not confirmed for sure one or both alternators have failed. In advance of the weekend, I did some price checking. Local F-dealer has one in stock new for $1092. Eurospares had a new for 415 Lb Sterling or 200 "good used". So I have fall back positions if replacement is required. Local dealer said units are Bosch and most people have them rebuilt. Other than the pulley I might try to find a match and buy a new Bosch and swap the pulley.

    This weekend I will sort out the need.
    Ken
     
  5. Fritz Ficke

    Fritz Ficke Formula 3
    Rossa Subscribed

    Jan 3, 2006
    2,266
    Tucson, AZ.
    Full Name:
    Fritz Ficke
    I took both my alternaters to a local alternater/starter repair shop, did not tell them what they came off and they did not ask. When I picked them up they had Fiat stickers on them and I was billed $115 for each. I have used these people professionally for over 20 years. Their rebuild's last longer than after market new and or only matched by new OEM.
     
  6. Ashman

    Ashman Three Time F1 World Champ
    Owner Silver Subscribed

    Sep 5, 2002
    33,257
    MA
    Full Name:
    John
    Absolutely no need to replace alternators when any competent electrical shop can rebuild them both for a small fraction of the cost of a single new one. The only thing that is difficult is removing and replacing them. The actual rebuilding is standard and easy.

    Good luck!

    John
     
  7. SouthJersey400i

    SouthJersey400i Formula 3

    Mar 14, 2007
    1,679
    Romulus, NY (Finger Lakes)
    Full Name:
    Ken Battle
    I have tested system pretty thoroughly including with the top alternator removed. At idle I get ~13.5 V and it only goes to 13.8 V at 2000 RPM or higher. This is with no or low load. When I bought the car the same test gave 13.5V and 14.0V, so alternators appear a bit weak. I applied load, fans and A/C and voltage at battery is a bit lower, maybe 13.5 at 2000 RPM. I removed the top alternator and retested and the numbers are about 0.2 V lower. It appears as long as I do not run A/C lights and such with the car at idle for a long time, I should not run the battery down; that is just a stop gap measure. Both charging lights on the speed are out whenever the engine is running.

    Having removed one alternator, I see that a rebuild is quite easy, since all of the components that usually fail are bolted on the outside of the alternator. My plan will be to find a good shop that rebuilds Bosch units and get him to test / rebuild the top one first. The lower one can be removed without too much hassle since a PO ground one side of the head of the bolt off to clear the steering component; I had it out when I replace the belts.
    Ken
     
  8. FERRARI-TECH

    FERRARI-TECH Formula 3

    Nov 9, 2006
    1,677
    Los Angeles
    Full Name:
    Ferrari-tech
    Voltage is not the test of an alternator, load is measured by current draw, i.e amps.. 14v means nothing if the alternator is charging at 1 amp.... test each altenator seperatly.. either on or off the car but look for amps..............depending on model i would be looking for 50-70 amps
     
  9. Ashman

    Ashman Three Time F1 World Champ
    Owner Silver Subscribed

    Sep 5, 2002
    33,257
    MA
    Full Name:
    John
    IIRC sitting here at the kitchen table, I think the 400i alternators are rated at 55 amps each.
     
  10. SouthJersey400i

    SouthJersey400i Formula 3

    Mar 14, 2007
    1,679
    Romulus, NY (Finger Lakes)
    Full Name:
    Ken Battle
    If the alternator is in the car, what is the best way to put a load on it? Is there a test box for that? IF so I think I can borrow one from my local parts place. I know I can turn on A/C, lights etc. and have ammeter in the power line from the alternator.

    I will be calling local shops to see who has best story about testing and repairing Bosch alternators. I will likely leave it to them.
    Ken
     
  11. markcF355

    markcF355 F1 Rookie

    Jun 6, 2004
    3,493
    Schmeckelstan
    Full Name:
    Mark
    Ken,
    You might have a problem with your AC compressor clutch sticking (or engaged if you have enough oil pressure to fool the AC system into thinking the engine is running while cranking). The starter with just a single battery won't be able to turn the motor when this happens.
     
  12. SouthJersey400i

    SouthJersey400i Formula 3

    Mar 14, 2007
    1,679
    Romulus, NY (Finger Lakes)
    Full Name:
    Ken Battle
    Mark
    I think I am convinced that I am just not getting enough amps out of the two alternators. The battery is really dead when it will not spin the motor, with a quick charge the car starts fine.

    I have a shop to check the alternator now, but it will be 2-3 weeks before I get it to him. I have a backup plan for upcoming trips!
    Lem
     
  13. SouthJersey400i

    SouthJersey400i Formula 3

    Mar 14, 2007
    1,679
    Romulus, NY (Finger Lakes)
    Full Name:
    Ken Battle
    I pulled the alternator and brought it to a garage I just found that does electrical work. He pulled unit apart and tested all of the components that he could test without having a bench to spin the unit. We concluded the easiest thing to do was to replace the voltage regulator / bushes unit. It is Bosch Part # 1-197-311-028 and cost only $48. It takes about 5 minutes to swap in the new unit; it is external and held in by two small bolts.

    I retested same conditions of load and voltage (unable to measure amps) and it gives 0.4-0.6 V higher reading at the same load conditions. These readings are now the same as when I bought the car 2 years ago (almost my second anniversary).

    So I think I have solve my problem. Over the winter I may just buy a second regulator unit and swap out the lower one. If I have enough space I may not even have to remove the alternator from the car!?
    Ken
     
  14. markcF355

    markcF355 F1 Rookie

    Jun 6, 2004
    3,493
    Schmeckelstan
    Full Name:
    Mark
  15. markcF355

    markcF355 F1 Rookie

    Jun 6, 2004
    3,493
    Schmeckelstan
    Full Name:
    Mark
    While looking around, I found that www.rockauto.com has rebuilt alternators for SII cars for around $70 without a core.

    Search for a 1980 308 GTB alternator and you'll see it.
     

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