Guys, My F355 keeps losing battery power, and I am convinced the alternator is at fault. In short, please can someone tell me the best way to access and remove the alternator? Many thanks Narinder
Narinder don't be too hasty. Before deciding it's the alternator you should do a quick voltage check. Remove the RH engine bay cover to reveal the battery jump-start point (you can find instructions in the owners handbook). Connect a voltmeter to the + and - connection points. note down the voltage (which should be more than 12V if the battery is charged and OK). Start the engine and allow to idle. The voltage reading should increase if the alternator is OK. Once warm increase the engine speed and hold at 3,500 RPM. The voltage reading should be between 13.6 and 14.6 volts. If you see these readings then the alternator is OK. To do a rough check on the battery: switch off the engine, check battery voltage. If it is at least 12v turn on the ignition (don't start the engine), turn on the head lamps and the heated rear window. The battery voltage should hold steady at 12v for at least 4 minutes. If it drops below 10v then the battery is probably dud and you should get the battery properly tested with a discharge tester. If the tests are OK then you have something else draining the battery eg. alarm, hifi etc. in which case a battery tender is the answer. to answer the original question: Getting the alternator off is straight-forward. - Lift the car, remove the under-tray. - Slacken off the alternator belt tensioner centre nut. - Slacken the tensioner adjuster screw. - Disconnect electrical connector. - Unscrew alternator fixing bolts.
RF, Thanks so much for the detailed response. I should hav mentioned that the battery is brand new. I will do all of the checks that you menioned before going as far as the alternator. Thanks again.
In addition to all the stuff you have already been told A Put a ground strap on the alternator. B At that battery cable junction on the right side of the engine compartment, look for corrosion and tighten the 3 loose nuts. Those are the most common faults in the 355 charging system.
Rifledriver, Thanks for the tips. I have checked the connection in the engine bay, and they are tight and totally free from corrosion. When I get the alternator, I will check for the earth strap. However, I thought I read somewhere that Ferrari dealer were ading these on when the cars went in for servicing (the car has a full main agent history)? Cheers.
If it has one it will be obvious, they are not hidden. If you did not have to remove it when you removed the alt, it does not have one. I would not count on the dealer already having done it. Some are better about it than others. I see cars from the factory owned store all the time without them.
If you do put a strap on the alternator to the chassis, make sure the cable can take 150amps as I have seen a 355 with a thin wire that was put on completely burnt to a crisp! Alternately, Ferrari does make a ground strap for the 355. #180904 - and the last time I bought one they were £13.90. Cheers Paul
Brian, you were right. Now that we have got to the alternator, there is no ground strap! Could this alone be preventing the alternator from working correctly? Thanks.
YES! I am surprised you car does not have the ground strap. I was told that this problem was identified during the 96 or 97 years of production and added at that time....thus it was only the earlier cars the required this addition. Maybe this information was incorrect? I have heard this ground strap can fix a number of drivability issues as well. Such as "check engine" lights and such.
Hi Brian, A few days ago I found out my 99 355 does not have a ground strap on the alternator. Was it optional at the factory? --tony edit-> Never mind!, I read the rest of the thread and found my answer.
Dave - I don't think Ferrari identified the problem that early. My car is a late 98 spider and did not have the ground strap. I had charging problems as this person described. Karl added the strap and it has been trouble free since.
None of the cars came with a ground strap. The biggest problem cars were the 95's but the problem by no means ended there. All 355's should have one installed.
An easy check is to go to an auto parts store and buy a volt meter that plugs into your cig. lighter. Cost about $15. Plug it into the lighter and read the voltage , then start the car . Should read 11-12V before start and 13.6-14V at idle .
If I catch you correctly guys, the alternator is so isolated that the ground connection can not be establish via anything else than the ... alternator connection? I was myself expecting a ground connection via the alternator shell. May be a did not catch something. Christophe.
Hi Christophe, the alternator on the 355 is mounted with rubber isolating bushes and plastic sleeves around the bolts. The earthing through the casing is virtually non-existant, it's crazy. A basic mistake. RF.
The easiest way to check for a faulty alternator is to drive the car to an AutoZone or Pep Boys and have them check it with an auto electrical diagnostic machine for free. That's how I found out that the alternators on my BB512i were bad.
i believe I connected it to one of the bolts on the alternator casing, or to the grounding lug that is present there. There should be one, I forget.
